Applequist, W.L. (2016). A revision of the Malagasy Species of Homalium Sect. Eumyriantheia Warb. (Salicaceae). Candollea 71: 33–60. In English, English and French abstracts. DOI : http://dx.doi.org/10.15553/c2016v711a7
Homalium sect. Eumyriantheia Warb. (Salicaceae) is the largest and most widespread fasciculate-stamened section of Homalium Jacq. Though the section is markedly heterogeneous, the Malagasy species appear to form a natural group. A new revisionary treatment of these species is presented and an identification key is provided.Fifteen species are recognized, of which five, i.e. Homalium dorrii Appleq., Homalium pseudoboinense Appleq., Homalium randrianasoloi Appleq., Homalium ranomafanicum Appleq., and Homalium schatzii Appleq., are newly described. Occasional hybridization is observed. Most species are endangered.
Introduction
Homalium Jacq. is a pantropical woody genus that is now placed within Salicaceae, along with many other genera of the polyphyletic former Flacourtiaceae (Chase et al., 2002 ; Alford, 2005). Homalium is one of the largest of these genera, including up to 150 recognized species (Applequist, 2013), as well as an unknown number of unrecognized species in regions where the existing treatments are obsolete.The genus is characterized by hermaphroditic flowers with semi-inferior ovaries and conspicuous single raised glands at the base of each sepal ; fruits are very small with few maturing seeds, and flowers are usually dehiscent as a unit before seeds mature. As currently circumscribed, the genus encompasses an unusually broad range of floral morphology (e.g., there is substantial variation in petal and sepal number, shape, indument and accrescence, anther morphology, stylar morphology, shape of the fruiting ovary, and locular pubescence ; Applequist, unpubl. data). The last worldwide survey of Homalium was by Warburg (1894), who published a complex classification of two subgenera (subg. Blackwellia Warb., and Homalium, defined by solitary (per-petal) vs. fasciculate stamens respectively), and nine sections. This classification has been largely maintained, though later authors have made some nomenclatural corrections and proposed additional sections, not all of which appear useful.
Madagascar represents perhaps the most important center of diversity for Homalium ; six sections are present, four of which have previously been considered endemic. The last revisionary treatment of the Malagasy species of Homalium (Sleumer, 1973) recognized 36 species. The amount of herbarium material from Madagascar available now, compared to 40 years ago, has increased enormously, and examination of collections indicated that multiple unnamed species were present. Updated revisions of all sections are therefore being prepared. Homalium sect. Eumyriantheia Warb. is one of the most speciose sections in Madagascar, and the only section present that belongs to subg. Homalium. As traditionally circumscribed, it occurs in Asia and the Pacific as well as Madagascar. However, the author will propose a revised classification of Homalium in which the Asian and Pacific species of sect. Eumyriantheia, which have far less morphological similarity to the Malagasy species of that section than to single-stamened Asian species, will be segregated into sect. Polyanthera Warb. Under this treatment, sect. Eumyriantheia will represent a fifth endemic section in Madagascar (Applequist, unpubl. data).
Material and methods
Herbarium specimens at Paris (P) and St. Louis (MO) were examined, as were then-undistributed duplicates for exchange available at those herbaria and images available through JSTOR of types held by other institutions. Definition of species utilized a taxonomic species concept (e.g., Grant, 1981), the most widely used and usually most practical approach in plant taxonomy; three fixed morphological differences suffice to recognize taxonomic entities at the species level, with conspicuous ecological preferences potentially being considered as supporting characters (in practice, this is necessary only in the “Homalium capuronii Sleumer species complex”, in which species are on average distinct but encompass a range of variation that can make extremes hard to formally distinguish). Preliminary evaluation of conservation status according to the IUCN Red List Categories and Criteria (IUCN, 2012) was performed for each species recognized.
Taxonomic treatment
Homalium sect. Eumyriantheia Warb. in Engler & Prantl, Nat. Pflanzenfam. III(6a) : 36.1893.
≡ Myriantheia Thouars, Gen. Nov. Madagasc.: 21.1806. ≡ Homalium [unranked as §] Myriantheia (Thouars) Baill. in Bull. Mens. Soc. Linn. Paris 1 : 576. 1886 [as Myrianthea]. ≡ Homalium sect. Myriantheia (Thouars) Kuntze in Post & Kuntze, Lex. Gen. Phan., Prop.: 285. 1903 [as Myriantheja].
Typus : Homalium laxiflorum (Tul.) Baill. (≡ Myriantheia laxiflora Tul.) (designated by Sleumer, 1973 : 315).
Trees. Leaves with stipules usually caducous (rarely in part persistent) ; secondary veins brochidodromous, little or not prominent ; texture fairly thick to coriaceous. Inflorescences racemose or paniculate, lateral (in part pseudoterminal or clustered at apices) ; flowers pedicellate (sessile), often with bracteoles borne on pedicels, dehiscing immediately or slightly below flower shortly after anthesis. Flowers with sepals and petals numbering 4 to 5 (seldom 6), not markedly accrescent nor highly reduced ; sepals not (or inconsistently) reflexed ; petals obovate to oblanceolate (in H. trigynum to spatulate, with sepals then ovate), not ciliate (except through pubescence of entire adaxial surface) ; calyx cup usually more or less funnelform (rarely shortly so, or in H. trigynum cylindrical with a broad rounded base) ; stamens inserted just below base of, but not adnate to petals in groups of 3 (aberrantly 4 ; in H. boinense consistently 5) with two in each fascicle attached at the sides of the neighboring sepal glands ; anthers 0.2–0.5 mm, dorsifixed below midpoint and often somewhat versatile, dehiscing by longitudinal sutures, united by a broad connective so that the thecae are parallel or almost parallel with their adjoining lateral surfaces appressed ; styles fused at base. Fruits, where known, usually containing 1 to 2 maturing seeds (possibly several-seeded in one species) ; inner surface of ovary glabrous (sparsely pubescent).
Notes. — Sleumer (1973) wrongly corrected the name of sect. Eumyriantheia to Myriantheia and treated it as having been based upon the generic name Myriantheia Thouars. Under Art. 21.3 of the ICN (McNeill et al., 2012), Eumyriantheia could not have been validly published as a section within Myriantheia if that genus had been recognized, but it is legal within Homalium. Myriantheia does not enjoy priority at the sectional level, and Eumyriantheia could have been published either as a replacement name for it or as the name of a new taxon. However, since Sleumer considered the two to be nomenclatural synonyms, his designation of a type for one of them can be considered applicable to both.
The traditional circumscription of sect. Eumyriantheia is excessively broad. It was distinguished from other fasciculate-stamened sections largely by its lack of the apomorphic characters that were said to characterize those sections ; thus it has been defined by plesiomorphic characters, and encompassed a suspicious degree of variation. South Asian, Malesian and Pacific species (see Sleumer, 1954 ; Lescot, 1970,1980) have 7 to 12 (rarely 6) narrowly oblong to narrowly elliptical sepals and petals, which are similar in shape, or the sepals shorter and narrower, and long-ciliate or long-pubescent throughout ; the calyx cup is usually subcylindrical and prominently ridged and the anthers very small in proportion to the long slender filaments. Flowers of most of these species closely resemble typical flowers of the widespread sect. Blackwellia, except that sect. Blackwellia has only 1 stamen per petal.
By contrast, the Malagasy species of sect. Eumyriantheia (including the type of the section) have 4 to 5 (rarely 6) sepals and petals, which are relatively broad and variable in shape (the petals often being obovate) and lack long cilia ; the calyx cup is usually funnelform or cup-shaped and the anthers different in shape and usually larger. In overall appearance, these species bear much less resemblance to the fasciculate-stamened Asian and Pacific species than to some solitary-stamened Malagasy species. The distribution of morphological variation in Homalium (and allied genera such as Calantica Jaub. ex Tul.) makes it evident that some character(s) must have evolved homoplasiously. It is this author's opinion that changes in stamen number are clearly homoplasious, and that neither subg. Homalium nor subg. Blackwellia as traditionally defined are natural groups.The exclusion of the Asian and Pacific species from sect. Eumyriantheia into a restored sect. Polyanthera will therefore be proposed (Applequist, unpubl. data).
Almost no fruiting material is available of sect. Eumyriantheia, as recircumscribed to comprise only the Malagasy species ; fruits with large (to 2 mm) developing seeds are very rare even in well-collected species. It appears that fruits dehisce promptly as seeds mature. Most flowering parts, except for anthers, usually persist until the maturing fruit is lost as a unit. Species circumscriptions and keys therefore rely solely on flowering characters.
Key to the Malagasy species of Homaliumsect. Eumyriantheia
1. Stamens in groups of 5 ; dry forest, Mahajanga 1. H. boinense
1a. Stamens in groups of 3 (aberrantly 4) ; humid and littoral (very rarely to dry) forests, widespread 2
2. Calyx cup cup-shaped, usually elongated, or cylindrical with a broad rounded base ; pedicel 0.5–1 (rarely to 3) mm or absent ; petals < 3.5 mm with acute apices 15. H. trigynum
2a. Calyx cup usually funnelform at anthesis (to cup-shaped in fruit or rarely cylindrical) ; pedicel usually > 1 mm ; petals variable, usually > 3.5 mm (rarely < 3.5 mm then apices rounded) 3
3. Abaxial surface of both sepals and petals densely (to moderately) pubescent over most of surface, often less dense at apical margins 4
3a. Abaxial surface of sepals and petals sparsely or minutely pubescent to glabrous, or portions of the petals densely pubescent but the sepals glabrous to sparsely (moderately) pubescent (in one species moderately pubescent, densest at base and along margins) 7
4. Upper surface of sepal glands at least partly pubescent 9. H. oppositifolium
4a. Upper surface of sepal glands glabrous 5
5. Sepals 4 (rarely 5), 3–5.5(-6.5) mm, broadly oblong to broad-based obovate or oblong (rarely broadly elliptical) with rounded apex ; petals 3.6–6.2 mm, normally significantly longer than sepals (aberrantly equal in length) ; neither petals nor sepals at all keeled ; petals very densely pubescent at least near base, with fairly short trichomes H. laxiflorum
5a. Sepals 5 (seldom 4 or 6 in H. brevipedunculatum), 4.5– 8.4 mm, oblong-lanceolate or elliptical (to obovate) with acute (to obtuse or rounded) apex ; petals 4.5–9 mm, slightly longer than (about equal to) sepals ; petals and/ or sepals usually slightly keeled towards apex ; petals usually in part densely sericeous with long trichomes 6
6. Leaves subopposite to alternate (especially proximally), obovate (narrowly or broadly obovate, elliptical), (3.7-) 5.1-11 × 2.1-5.8(-6.5) cm with petiole 3–12(-17) mm ; inflorescences 1.5–4(-5.3) cm ; abaxial surface of sepals and petals densely pubescent to sericeous (usually only on petals) ; sepals often shallowly keeled only at apex, petals usually shallowly keeled ; petals oblanceolate to narrowly obovate, 4.5-8.5 × 1.8-3 mm 2.H. brevipedunculatum
6a. Leaves usually alternate (seldom subopposite), elliptical to obovate (broadly obovate), (5.5-)6.5-18 × (3-)4-9 cm with petiole 7–23 mm ; inflorescences (1.5-)2.3-10(-13.5) cm ; abaxial surface of petals and sometimes sepals densely sericeous ; sepals usually shallowly keeled for half or more of length, petals usually with a thick streak of very dense indument along central axis but not noticeably keeled ; petals obovate to broadly obovate with a narrowed base, 5.5-9 × 3.4-5 mm 8.H. nobile
7. Sepals 5.5–6.6 mm, petals 9–10.5 mm ; abaxial surface of sepals usually with a conspicuous broad pale margin more densely pubescent than remainder of surface 10.H.pseudoboinense
7a. Sepals to 4.6 mm, petals to 6.5 mm ; abaxial surface of sepals glabrous to sparsely (moderately, minutely) pubescent throughout, the indument not denser near margins 8
8. Upper surface of sepal glands densely (to moderately) pubescent 9
8a. Upper surface of sepal glands glabrous to glabrate, or sparsely or partially pubescent 11
9. Leaves narrowly obovate to narrowly elliptic or oblongelliptic or obovate ; sepals 3.7–4.6 mm ; petals moderately longer than sepals ; littoral or low-elevation forest 4.H. dorrii
9a. Leaves elliptical (to narrowly or broadly elliptical, obovate) or broadly obovate (to obovate, broadly elliptical) ; sepals < 3.5 mm ; petals almost twice as long as sepals ; mid-elevation humid forest 10
10. Leaves elliptical (to narrowly or broadly elliptical, obovate) ; leaf margins toothed or wavy with multiple glands in marginal projections ; inflorescences racemose 7.H. maringitra
10a. Leaves broadly obovate (to obovate, broadly elliptical) ; leaf margins revolute, often strongly, to subentire with 0 to 2 basal glands sunk in margins ; inflorescences paniculate with well-developed branches 13.H. ranomafanicum
11. Inflorescences all or almost completely racemose, with flowers borne singly or in groups of 1–3 on a ridged rachis (at most, clustered flowers rarely forming a very short branch) 12
11a. Inflorescences paniculate, sometimes spiciform with most flowers borne in clusters on short side branches 13
12. Leaves oblanceolate to elliptical or narrowly elliptical, 4-9(-13.7) × 1.5-3.6(-4.4) cm ; base cuneate to convex or attenuate ; apex cuspidate to rounded (acute) ; leaf margins with 2–4 small basal glands per side ; rachis and pedicels usually glabrous (sparsely pubescent) ; sepal glands 0.6-1 × 0.4–0.5 mm ; abaxial surface of petals pubescent with short appressed hairs most densely on central basal portion, less so towards margins, usually with a dark line down the center but not a broad glabrate stripe ; Toliara 11. H. pulchrum
12a. Leaves elliptical to obovate, 6-11.5 × 2.8-6.2 cm ; base convex ; apex rounded to rounded-cuspidate, roundedobtuse or emarginate ; leaf margins with 1–2 small basal glands per side ; distal part of rachis and pedicels minutely pubescent ; sepal glands 0.9-1.6 × 0.7-1 mm ; abaxial surface of petals moderately to densely short appressedpubescent with a conspicuous glabrate stripe along the central axis ; Toamasina 14. H. schatzii
13. Leaf margins crenate-serrulate for most of length ; panicles borne mostly in pairs along length of older twigs, with an open slender appearance, many having one or more well-developed lower branches sometimes subtended by foliose bracts ; petals usually only slightly longer than sepals ; sepal glands entirely glabrous ; lowelevation forest, Antsiranana 5.H. graciliflorum
13a. Leaf margins subentire or revolute (occasionally with few glandular teeth) ; panicles borne singly except when clustered at twig apices, usually confined to younger distal portions of twigs, usually mostly spiciform with very short branches (in part with few well-developed branches, these then not subtended by foliose bracts) ; petals normally significantly longer than sepals ; sepal glands sometimes in part sparsely pubescent in the depressed central portion 14
14. Leaves obovate to elliptical, often broadly (rarely to suborbicular, narrowly elliptical, or oblanceolate), (2.5-)4-7.5(-10.2) × (1.5-)2.1-4.3(-5.1) cm ; base cuneate to convex (slightly attenuate) ; apex rounded (rounded-obtuse, shallowly emarginate or rounded-cuspidate, rarely acute or short-acuminate with a rounded tip) ; margins revolute to subentire or bearing few shallow teeth, with small glands sometimes present and variably placed ; panicles normally all spiciform ; sepals and petals 4 ; high- to midelevation forest ; Antsiranana 3 . H. capuronii
14a. Leaves elliptical to obovate or broadly (narrowly) elliptical, 6-12.5 × 2.8-6.6 cm ; base convex to rounded, at extreme base short-attenuate ; apex rounded-acute to cuspidate, rounded, or shallowly emarginate ; margins minutely revolute with 0 to 2 basal glands just inside margin ; panicles sometimes with short but well-developed lower branches ; sepals and petals 4(-5) ; low-elevation forest ; Toliara (Marovony) 12. H. randrianasoloi
1. Homalium boinense H. Perrier in Mém. Mus. Natl. Hist. Nat. 13 : 297. 1940.
Lectotypus (first step, designated by Sleumer, 1973 : 318) : Madagascar. Prov. Mahajanga : Beritzoka entre Maevatanana et Andriba, X.1892, fl., Perrier de la Bâthie 338 (P).
Lectotypus (second step, designated here) : Madagascar.Prov. Mahajanga : Beritzoka entre Maevatanana et Andriba, X.1892, fl., Perrier de la Bâthie 338 (P [P04679008]! ; isolecto- : G [G00018416] image seen, L [L0010885] image seen, P [P04679009]!). Syntypi : MADAGASCAR.Prov. Mahajanga : sine loc., 1898, fl., Perrier de la Bâthie 699 (P [P04679004]!, S [S10-10098] image seen) ; env. de M[a]evatanana, 1900, fl., Perrier de la Bâthie 6729 (P [P04679005]!, PRE [PRE0602253-0] image seen, US [US00603577] image seen) ; Mahamavo, W du Namakia, IX.1922, fl., Perrier de la Bâthie 14833 (K [K000231474] image seen, P [P04679006, P04679007]!).
Tree to 20 m tall ; large twigs brown ; young twigs brown, glabrous or sparsely and minutely pubescent ; stipules broadly deltoid (deltoid), 1–1.6 mm, minutely pubescent or glabrous. Leaves alternate ; petiole 5–15 mm, glabrous or sparsely minutely pubescent ; blade elliptical to broadly elliptical or obovate, 5.7-13.6 × 3.4-6.6 cm ; base rounded (minutely attenuate at petiole attachment) to convex (cuneate in immature leaves) ; apex rounded to rounded-obtuse or cuspidate ; margins subentire or shallowly wavy or toothed, then with small glands in tooth apices at margin ; abaxial surface glabrous or bearing few small hairs on midrib, drying brown ; adaxial surface glabrous, drying dark or pale grayish brown. Inflorescences narrowly paniculate, with flower clusters usually borne on short branches or flowers solitary distally, occasionally racemiform, lateral, 6.5–15 cm, short-pubescent ; peduncle (0.8-) 2-5.5 cm, moderately thick ; pedicel 1-2(-2.5) mm, densely short-pubescent ; bracts ovate to broadly deltoid or suborbicular, 1.3–3.4 mm, densely (to sparsely) pubescent ; bracteoles lanceolate (ovate), 1–2 mm, pubescent. Flowers : sepals 5(-6), narrowly oblong to narrowly elliptical or oblong-ovate with acute to rounded-acute (rounded) apex, 3–5.7 mm, abaxial surface moderately pubescent ; calyx cup shortly funnelform, densely short-pubescent especially basally ; sepal glands irregularly trapezoid to rectangular with a depressed center, 0.6-1.3 ×0.5-0.8 mm, upper surface usually densely short-pubescent ; petals white, obovate to oblanceolate, with rounded apex, 5.2-8 ×2.3-4 mm, conspicuously longer than sepals, abaxial surface densely short-pubescent especially basally, adaxial surface glabrous ; stamens in groups of 5 ; filaments 3–4 mm, glabrous ; anthers 0.4 mm ; ovary raised conic, densely short-pubescent ; styles 4, 1.4–2.3 mm, short-pubescent at base. Seeds not seen.
Uses. — The wood is said to be white, of good quality, and much used (Perrier de la Bâthie 14833).
Distribution, ecology and conservation status. — Homalium boinense is confined to dry forest in Mahajanga province. It is known from fewer than 5 locations ; its native range is unprotected and highly degraded, and it has not been collected for over 90 years. A preliminary conservation status assessment of “Endangered” [EN B2ab(iii)] following IUCN Red List Categories and Criteria probably underestimates the level of threat.
Notes. — Sleumer (1973) designated Perrier de la Bâthie 338 at P as the lectotype of Homalium boinense ; there are two sheets of this collection at P, both of which he marked “Syn & Lectotype”. Art. 9.17 of the ICN (McNeill et al., 2012) recommends that a second-stage lectotypification be published to select one of these sheets ; the selected sheet is in better condition and includes a fragment packet and what is probably Perrier de la Bâthie's original label.
Homalium boinense is notable for its stamens in groups of five, rather than three, and its habitat in dry regions of Mahajanga province, where no other species of sect. Eumyriantheia occur.
2. Homalium brevipedunculatum Scott-Elliot in J. Linn. Soc., Bot. 29 : 21. 1891.
Typus : Madagascar. Prov. Toliara : Fort-Dauphin, V.18??, post-fl., Scott Elliot 2600 (holo- : K [K000231468] image seen ; iso- : P [P00375087]!).
Tree to 20 m tall, 35 cm dbh ; large twigs dark gray to gray or dark brown ; young twigs grayish to pale brown, glabrous (to sparsely or partially pubescent) ; stipules narrowly lanceolate or linear, 1.7–2 mm, pubescent. Leaves subopposite to alternate especially proximally ; petiole 3-12(-17) mm, glabrous or sparsely (to moderately) pubescent when young ; blade obovate (narrowly or broadly obovate, elliptical), (3.7-)5.1-11 × 2.1-5.8(-6.5) cm ; base convex (cuneate, rounded) ; apex rounded to emarginate ; margins usually somewhat revolute, occasionally minutely toothed then with 1–5 glands toward base of leaf, rarely more ; abaxial surface sparsely pubescent on midrib (and blade), drying brown ; adaxial surface glabrous, drying brown (green). Inflorescences racemose, lateral, sometimes mostly confined to distalmost portion of twigs, 1.5-4(-5.3) cm, densely (to moderately) short-pubescent ; peduncle 0.3–0.8 cm, sturdy ; pedicel 1-2(-4) mm, densely pubescent ; bracts broadly ovate (ovate), (1.4-)2-3.8 mm, densely pubescent ; bracteoles ovate, sometimes apparently absent, 1.5–2.5 mm, densely pubescent. Flowers : sepals (4-)5(-6), greenish-beige to whitish or yellowish, narrowly oblong (oblong-elliptical, oblanceolate) with acute apex, 4.5–7.5 mm, abaxial surface densely to moderately pubescent (to sericeous), often slightly keeled at apex ; calyx cup funnelform (becoming cylindrical), densely to moderately pubescent (to sericeous) ; sepal glands yellow, conspicuously elevated, 0.9-1.3 × 0.9-1.3 mm, the upper surface glabrous and wrinkled, with pubescence underneath on abaxial surface ; petals greenish-white to white or yellowish-white, oblanceolate to narrowly obovate with a narrow base, acute to obtuse or rounded apex, 4.5-8.5 × 1.8-3.2 mm, slightly longer than or about equal to sepals, abaxial surface densely pubescent and often shallowly keeled, adaxial surface glabrous or rarely sparsely pubescent ; filaments white to yellowish, 2.4–3.8 mm, glabrous ; anthers yellow, 0.3–0.4 mm ; ovary short-conical, long-pubescent to pilose ; styles 3(-4), dark reddish green, 1.5–3.5 mm, basally long-pubescent. Seeds probably 1 per fruit ; mature seeds not seen.
Vernacular names. — “Maranikoditra” (Faliniaina et al. 37, Ramison et al. 139) ; “Rohandriana” (Service Forestier 6610, 7851).
Distribution, ecology and conservation status. — Homalium brevipedunculatum is native to littoral and low-elevation humid forests of southeastern Madagascar ; it is reported primarily on sand, but occasionally on laterite. Fewer than ten distinct locations are known, most close to Fort-Dauphin ; though these include some protected land, the remainder of its range is subject to ongoing forest loss, justifying a preliminary conservation status assessment of “Vulnerable” [VU B2ab(iii)] following IUCN Red List Categories and Criteria.
Notes. — Homalium brevipedunculatum most closely resembes, and co-occurs in part of its range with H. nobile ; the latter species has sometimes very large leaves, (5.5-)6.5-18 × (3-) 4-9 cm, with at least slight pubescence on the midribs, and petals 3.4–5 mm broad. The other common littoral species with racemose inflorescences and densely pubescent perianth, H. laxiflorum, has broader and on average shorter sepals and petals with rounded apices, with the petals usually well exceeding the sepals ; neither petals nor sepals are at all keeled, and their indument, though partly dense, is generally short.
Rabenantoandro et al. 954 from Mahabo (23°10′20″S 47°42′23″E ; MO) has flowers like those of H. brevipedunculatum, with narrow petals, and the leaf midribs are virtually glabrous, but the leaves are very large as is typical of H. nobile. Both species are known from Mahabo. It is suggested to be a hybrid between those species.
Additional material examined. — Madagascar. Prov. Fianarantsoa : S of Farafangana, near village of Mahabo, 23°10′51″S 47°42′29″E, 30 m, 5.XI.2001, fl., McPherson & Rabenantoandro 18358 (MO,P) ; Fkt. Nosy ala, forêt d'Analazaha,23°10′13″S 47°43′27″E, 22 m, 26.VIII.2003,fl., Rabehevitra et al. 558 (P). Prov. Toliara : Fort-Dauphin, fl., Cloisel 125 (P) ; forêt sur la route de Ste. Luce, partie S, 24°46′S 47°09′E, 0–10 m, 23.III.1989, post-fl.,
Dumetz 631 (MO,P) ; Fkt. Sainte Luce,24°46′41″S 47°10′04″E, 17.XII.2000, fl. and post-fl., Faliniaina et al. 37 (MO) ; Bemangidy forest, ca. 3 km E of Antsotso, along RN 12a, 24°34′05″S 47°12′38″E, 100 m, 10.II.2006, post-fl., Lowry et al. 6756 (MO,P) ; Ste. Luce region, Manafiafy, 24°47′S 47°10′E, 25 m, 19.X.1989, fl.,McPherson et al. 14168 (MO,P) ; few km NW of Manantenina, forêt d'Analalava, 24°13′S 47°21′E, 40 m, 28.X.1989, fl., McPherson 14274 (MO,P) ; N of town near village of Ste. Luce (Manafiafy), forest NW of village, 24°47′S 47°10′E, 20 m, 16.I.1990, post-fl., McPherson et al. 14808 (MO,P) ; Taolagnaro, forêt M 7, 24°57′31″S 47°00′02″E, 0–10 m, 6.X.2000, fl., Rabenantoandro et al. 333 (MO,P) ; Fkt. Sainte Luce, forêt sublittorale de S8, Hova site minier, 24°46′29″S 49°08′57″E, 6 m, 4.XI.2003, fl., Rabenantoandro & Ramisy 1540 (MO,P) ; Fkt. Sainte Luce, forêt d'Analavinaky, à l'W du village d'Ambandrika, 24°46′30″S 47°09′00″E, 21 m, 24.XI.2009, fl., Rakotovao 4736 (MO) ; sentier reliant Ampasy et Iaboakoho village, 24°35′57″S 47°09′31″E, 29.XI.2009, fl., Rakotovao et al. 4909 (MO) ; forêt d'Ambavarano, 24°57′32″S 47°02′07″E, 7 m, 11.XII.2006, fl, Ramison et al. 139 (MO) ; Ste. Luce, fkt. Manafiafy, forêt de Manafiafy, 24°46′08″S 47°10′14″E, 21 m, 30.XI.2002, fl., Randrianaivo et al. 865 (MO,P) ; Antsotso, forêt d'Ivohibe, 24°56′46″S 47°19′54″E, 386 m, XI.2005, fl., Razakamalala et al. 2458 (MO, P) ; Iaboko, Antsotso Avaratra,24°34′35″S 47°12′28″E, 25 m, 13.XII.2007,fl., Razakamalala et al. 4025 (MO,P) ; N of Ft. Dauphin on road to Ste. Luce, block S-9 of QUIT-FER, 24°47′S 47°11′E, 15 m, 12.XI.1990, fl., Schatz et al. 2999 (MO,P) ; Mandena, 19.XII.1952, post-fl., Service Forestier 6610 (P) ; Mandena, 3.XI. 1953, fl., Service Forestier 7851 (P) ; Vinanibe, à l'W de Fort-Dauphin, 7.XII.1968, fl., Service Forestier 28619 (P [2 sheets]).
3. Homalium capuronii Sleumer in Bull. Jard. Bot. Natl. Belg. 43 : 319–320. 1973.
Typus : Madagascar. Prov. Antsiranana : Massif d'Anjanaharibe, W district Andapa, 1000 m,29.XII. 1950, fl., Service Forestier 952 (holo- : P [P00375088]! ; iso- : G [G00018410] image seen, K [K000231473] image seen, L [L0539781] image seen, P [P04734072, P04734073, P04734077]!,TEF [TEF000229] image seen).
Tree to 30 m tall, 80 cm dbh ; large twigs brown to grayish ; young twigs brown (to grayish), often fairly thick, glabrous ; stipules deltoid, 0.4–0.7 mm, glabrous. Leaves alternate (to opposite, mostly at twig ends) ; petiole (3-)4-8 mm, glabrous ; blade obovate to elliptical, often broadly (rarely to suborbicular, narrowly elliptical, or oblanceolate), (2.5-)4-7.5(-10.2) × (1.5-)2.1-4.3(-5.1) cm ; base cuneate to convex (slightly attenuate) ; apex rounded (rounded-obtuse, shallowly emarginate or rounded-cuspidate, rarely acute with a rounded tip or short-acuminate) ; margins revolute to shallowly toothed or subentire with small glands sometimes present, not always associated with noticeable toothing ; abaxial surface glabrous, drying medium brown (greenish) ; adaxial surface glabrous, drying pale brown or greenish to grayish brown. Inflorescences normally spiciform paniculate with most flowers clustered on short branches, lateral, mostly borne on distal portions of twigs, (2-)3-9(-12) cm, glabrous or the rachis minutely pubescent ; peduncle (0.2-)0.5-4(-6) cm, slender ; pedicel (0.5-)1-4 (-4.5) mm, sparsely minutely pubescent ; bracts ovate to broadly ovate or deltoid (lanceolate), 0.7–2.7 mm, glabrous or sparsely pubescent ; bracteoles deltoid to ovate or broadly deltoid, 0.3–1.5 mm, sparsely pubescent or glabrous, sometimes absent. Flowers sepals 4, greenish white or green on abaxial surface and white on adaxial surface (to reddish?), oblong to elliptical, narrowly oblong or elliptical, or ovate with rounded (roundedobtuse, rounded-acute) apex, 2.5-4(-5.3) mm, abaxial surface glabrous or sparsely pubescent ; calyx cup funnelform, sparsely and minutely pubescent ; sepal glands yellow, irregularly rectangular to elliptical, 0.6-1.3 × 0.4-0.6 mm, upper surface glabrous or sparsely short-pubescent (to moderately, only in the depressed center) ; petals greenish white to white (to reddish?), obovate to narrowly obovate (rarely to oblanceolate ; usually ascending rather than spreading) with rounded apex, 3.5-5.7(-6.7) × 1.8-2.6(-3) mm, usually significantly longer than sepals, abaxial surface minutely pubescent on lower central portion, sometimes densely at base, to glabrous at apical margin, sometimes with a dark line down the center, adaxial surface glabrous ; filaments white, 1.2–2.8 mm, glabrous ; anthers white becoming yellow then brown, 0.2– 0.3 mm ; ovary nearly flat in early anthesis to conic, moderately appressed-pubescent ; styles white, 4, (0.7-)1-1.5(-2.5) mm, if long then fused for up to a third of length, short appressedpubescent at base. Seeds 1 per fruit, subglobose, 1.8–2.1 mm.
Uses — Homalium capuronii is said to have hard wood, though there is no explicit documentation of ethnobotanical use.
Distribution, ecology and conservation status. — Homalium capuronii is native to humid forest in the northern province of Antsiranana ; it is reported to occur on gneiss and granite, and at moderate to high elevations. Only five distinct locations are known ; the species is rarely collected and anthropogenic damage in the area is ongoing. Hence, a preliminary conservation status assessment of “Endangered” [EN B2ab(iii)] following IUCN Red List Categories and Criteria is appropriate.
Notes. — Homalium capuronii belongs to a group of species, also including H. graciliflorum, H. pulchrum, H. randrianasoloi, and H. schatzii, which have small flowers with sparsely pubescent or glabrous sepals and sepal glands. Material of the species in this group is limited ; all appear to be rare, and usually of limited distribution. Since their flowers are rather similar, and all have glabrous twigs and leaves and minutely pubescent (in 1 species to glabrous) inflorescences, they can be difficult to differentiate. Table 1 summarizes the most conspicuous variable characters. Homalium capuronii usually has leaves of modest size (usually < 7.5 cm, rarely to 10.2 cm), with mostly rounded apices (one aberrant specimen, Derleth 107, has all short-acuminate apices) and mostly revolute or subentire margins, and spiciform panicles, which are confined to younger twigs and twig apices, with flowers mostly borne in clusters on very short branches. It is the only species of this group found at mid-to-high elevations in northern Madagascar, and is unusually variable in appearance despite the limited number of specimens known.
Schmidt et al. 4339 from the Anjanaharibe-Sud Special Reserve (14°43′56″S 49°28′13″E, from at least 1400 m altitude ; MO) resembles Homalium capuronii except that the inflorescences are well-developed panicles with multiple branches at least slightly elongated ; further, the sepal glands are much more densely pubescent than is normal for this species. Typical H. capuronii has also been collected from the Reserve. It is tempting to identify this specimen as a hybrid, but the only potential second parent that occurs in medium- or higher-elevation northern forests is H. oppositifolium, which is not known from the location, and which has racemose inflorescences so might be assumed unlikely to produce a hybrid with more paniculate inflorescences. Further investigation of this population would be highly desirable.
Additional material examined. — Madagascar. Prov. Antsiranana : Manongarivo, Mont Antsatrotro, 14°05′01″S 48°23′18″E, 1780 m, 14.II.1994, fl., Andrianarisata et al. 200 (BR, K, MO) ; Manongarivo, vallon en amont de la chute de la rivière Bekolosy, 14°02′S 48°18′E, 1100 m, 22.VIII.1994, fl., Derleth 107 (MO, P) ; Massif de l'Anjanaharibe (pentes et sommet N) a l'W d'Andapa, 10.XII.1950-3.I.1951, post-fl., Humbert et al. 24560 (P) ; Manongarivo massif, above village of Ambodisakoana, 14°05′S 48°20′E, 1100 m, 17.X.1994, fr.,McPherson & van der Werff 16390 (MO) ; ibid. loc., ridge above camp, 1100–1175 m, 19.X.1994, fr., McPherson & van der Werff 16420 (MO) ; Daraina, forêt de Binara, 13°15.83′S 49°35.94′E, 1015 m, 18.XI.2005, fl., Nusbaumer & Ranirison 1626 (MO,P) ; Antanambao Belinta, W du campement II, 13°39′14″S 48°40′06″E, 937 m, 3.XI.2007, fl., Rakotovao et al. 3893 (MO, P) ; Manantenina, Mandena, E de la vallée de Beondrika, rivière Beamalona, 14°29′S 49°49′E, 8.XII.2004, fl., Ravelonarivo 1337 (G, MO) ; Anjanaharibe-Sud, village de Mandritsarahely, suivant la rivière de Andranomenabe, 14°43′10″S 49°27′12″E, 1700 m, 14.II.1995, fl., Ravelonarivo & Rabesonina 635 (G, MO) ; Massif du Manongarivo, plateau du Bekolosy, vers 1200 m, 13.XI.1954, fl., Service Forestier 11447 (P).
4. Homalium dorrii Appleq., spec. nova (Fig. 1,2A).
Typus : MADAGASCAR. Prov. Toamasina : Analalava, 2.8 km W of old fortress at Foulpointe, 3.XII.1985, fl., Dorr et al. 4432 (holo- : MO-3320333! ; iso-, P [P04705567, P04705569]!).
Homalium dorrii Appleq. differs from H. maringitra H. Perrier in having narrowly obovate to narrowly elliptic leaves with cuneate to convex bases, subopposite or clustered near twig ends, and longer sepals.
Tree to 10–15 m tall, 6 cm dbh ; large twigs dark or grayish brown ; young twigs gray-brown to pale whitish gray, glabrous ; stipules deltoid, 1 mm, glabrous. Leaves clustered at twig apices or on short branches or subopposite, leaf scars on older twigs occasionally whorled ; petiole 5–11 mm, glabrous ; blade narrowly obovate to narrowly elliptic or oblong-elliptic or obovate, 4.2-9 × 1.6-4 cm ; base convex to cuneate ; apex rounded ; margins slightly revolute, shallowly and irregularly denticulate with few teeth, glands located in teeth ; abaxial surface glabrous, drying brown ; adaxial surface glabrous, drying dark brown. Inflorescences racemose, lateral, often clustered near twig apices, 4.5–9 cm, sparsely short-pubescent (to moderately pubescent distally) ; peduncle 0.3– 4 cm, moderately thick ; pedicel 1–4 mm, short-pubescent ; bracts very few, deltoid, 0.5–1 mm, minutely pubescent ; bracteoles not seen (absent or caducous and not leaving obvious scars). Flowers sepals 4–5, broad-based obovate to nearly oblong with rounded apex, 3.7–4.6 mm, abaxial surface moderately (sparsely) shortpubescent on basal half, sparsely pubescent toward apical margin ; calyx cup funnelform (becoming convex in fruit), ridged, shortpubescent ; sepal glands roughly elliptical, 1-1.2 × 0.5-0.6 mm, upper surface densely short-pubescent ; petals white or whitish-grey, obovate with rounded apex, 4.8-5.4 × 2-2.6 mm, moderately longer than sepals, abaxial surface short appressed-pubescent mostly at base and in center, adaxial surface glabrous ; filaments ca. 1–1.5 mm, glabrous ; anthers 0.3 mm ; ovary conic (becoming hemispherical in fruit), short-pubescent ; styles 4, ca. 1 mm, basally short-pubescent. Seeds 1 per fruit, subglobose, 2–2.5 mm.
Distribution, ecology and conservation status.—The two known collections of H. dorrii are from the forest of Analalava near Foulpointe, at a low elevation near the coast, on laterite. The small number of collections suggests that the species is rare, since the area around Foulpointe was repeatedly botanized over several decades. Though the location had until recently been subject to ongoing degradation, it is now effectively protected. Thus, given the lack of knowledge regarding this species, a preliminary conservation status of “Data Deficient” [DD] seems most appropriate.
Homalium dorrii is presumed to be most closely related to H. maringitra and the newly described H. ranomafanicum, which have generally similar floral morphology (small flowers with sparse sepal indument but dense sepal gland indument). Both of those species have usually broader, elliptic to broadly obovate or obovate, at least partly alternate leaves and short sepals (to 3.5 mm in H. maringitra) that are often barely more than half as long as the petals ; both are native to mid-elevation humid forests. Homalium dorrii must also be distinguished from H. oppositifolium, which is found in eastern littoral forests and has often similarly shaped leaves and densely pubescent sepal glands. Homalium oppositifolium has a densely (to moderately) pubescent perianth, as well as denser and longer pubescence on the rachis and pedicels and sometimes on the petiole and leaf midrib ; the sepals are 5–6 in number and often narrow, and the bracts and bracteoles more numerous and sometimes quite large.
Paratypus. — Madagascar.Prov. Toamasina: Fkt. Morarano, forêt d'Analalava, à 7 km du SW de Foulpointe, 17°42′32″S 49°27′33″E, 43 m, 8.III.2005, post-fl., Birkinshaw et al. 1434 (P [P04734868]).
Table 1.
- Comparison of key features of species in the Homalium capuronii Sleumer group. Apparent differences in stamen and style size are excluded because of limited material.
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continued
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5. Homalium graciliflorum Sleumer in Bull. Jard. Bot. Natl. Belg. 43 : 321. 1973.
Typus : Madagascar. Prov. Antsiranana : Sambava, Mandrangotra [13°59′S 50°00′E], 23.II.1957, fl., Service Forestier 2788 (holo- : P [P00723726]! ; iso- : L [L0010923] image seen).
Tree to 12 m tall, 20 cm dbh, with grayish-white bark ; large twigs reddish or grayish brown ; young twigs pale grayish brown to pale brown, glabrous ; stipules not seen. Leaves primarily alternate ; petiole 3–7 mm, glabrous ; blade elliptical (narrowly elliptical), 5.8-10.5 × 2.3-4.7 cm ; base convex ; apex cuspidate to short-acuminate, with a rounded tip ; margins crenate-serrulate for much of length, sometimes with variably located glands ; abaxial surface glabrous, drying brown, sometimes paler than upper surface ; adaxial surface glabrous, drying brown. Inflorescences paniculate often with well-developed lower branches, the flowers single or in clusters, (2.5-) 6–12.5 cm, lateral, often paired, at least sometimes borne along the length of older twigs, also somewhat clustered at twig apices, proximally glabrous, the rachis minutely pubescent especially distally ; peduncle (0-)1.7-3.6 cm, slender ; pedicel (1-)2-6 mm, minutely pubescent ; major branches sometimes subtended by foliose bracts 6-9(-20) mm long ; bracteoles usually 1 per flower, broadly deltoid to deltoid, 0.4-0.8(-1.5) mm, minutely pubescent. Flowers: sepals 4–5, with pink margins in bud, oblong to ovate with rounded apex, 3.8– 5 mm, abaxial surface minutely pubescent ; calyx cup shortly funnelform, minutely pubescent ; sepal glands yellow, irregularly oblong to trapezoidal, 0.7 × 0.3-0.4 mm, upper surface glabrous, corrugated ; petals narrowly obovate with a narrowed base, rounded apex, 4-5.6 × 1.6-2.5 mm, slightly (to moderately) longer than sepals, abaxial surface appressed-pubescent mostly at base and in center sometimes with a sparsely pubescent dark line down center, adaxial surface glabrous ; filaments ca. 0.5–1 mm, glabrous ; anthers 0.2 mm ; ovary conic, villous ; styles 4 or 5, possibly 0.5–1 mm, villous at base. Seeds not seen.
Vernacular names. — “Tsidaitra [?]”, “Geravina” (Service Forestier 2788) ; “Zana” (Raharimampionona et al. 204).
Distribution, ecology and conservation status. — Homalium graciliflorum is known from low-elevation humid forest of the extreme north ; it is reported to occur on basalt and quartzite substrates. Only two collections are known, which are from locations quite close together ; remaining forest in that area is unprotected and subject to degradation. Hence, a preliminary conservation status assessment of “Endangered” [EN B1ab(iii)+2ab(iii)].
Homalium graciliflorum is part of the H. capuroniii group of rare species (see Table 1) with small flowers, sparsely pubescent sepals, and glabrous or sparsely pubescent sepal glands. It is distinguished by having consistently toothed leaf margins, panicles that are often borne in pairs and have often well-developed lower branches sometimes subtended by unusually large foliose bracts, and petals that are usually only slightly longer than the sepals. Homalium capuronii and H. schatzii also occur in northern Madagascar, though at much lower altitudes. Homalium capuronii is variable, but its leaves usually are less than 7.5 cm long and have rounded apices ; its leaf margins often lack teeth ; its inflorescences are usually confined to the distal portions of twigs and usually lack long branches (nor are there foliose bracts) ; and its sepals are usually much shorter than the petals. Homalium schatzii has sometimes broader leaves with subentire margins, racemose inflorescences, very large sepal glands, and unusual petal indument.
Additional material examined. — Madagascar. Prov. Antsiranana : Fkt. Ambavala, forêt d'Andohananjombalava dans le complexe Tsihomanaomby, 14°06′07″S 50°02′42″E, 88 m, 21.V.2008, fl., Raharimampionona et al. 204 (MO,P).
Fig. 1.
- Holotype of Homalium dorrii Appleq.
[Dorr et al. 4432, MO] [© Missouri Botanical Garden, Saint Louis. Reproduced with permission]
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Fig. 2.
- Flowers of newly described species of Homalium sect. Eumyriantheia Warb. A. Homalium dorrii Appleq. : flowers and nearly mature fruit with single seed ; B. Homalium pseudoboinense Appleq. : abaxial surface of perianth ; C. Homalium pseudoboinense : open flower ; D. Homalium randrianasoloi Appleq. ; E. Homalium ranomafanicum Appleq. ; F. Homalium schatzii Appleq. : open flower ; G. Homalium schatzii: abaxial surface of perianth.
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6. Homalium laxiflorum (Tul.) Baill. in Bull. Mens. Soc. Linn. Paris 1 : 575. 1886.
≡Myriantheia laxiflora Tul. in Ann. Sci. Nat., Bot. sér. 4, 8 : 66. 1857 [as Myrianthea].
Lectotypus (first step, designated by Sleumer, 1973 : 326) : Madagascar : sine loc. [Foulpointe ?], s.d., fl., du Petit-Thouars s.n (P)
Lectotypus (second-step, designated here) : sine loc. [Foulpointe?], s.d., fl., du Petit-Thouars s.n. (P [P04705839]! ; isolecto-: P [P04705842]!, P-JUSS n°14412 image seen). Syntypus : Madagascar: sine loc. [Foulpointe?], Chapelier s.n. (P [P04705840]!)
Tree to 14 m tall, 20 cm dbh, bark dark; large twigs dark brown (to gray, often streaky or patchy) ; young twigs grayish, glabrous (sparsely short-pubescent at apices) ; stipules broadly deltoid to deltoid, 0.7–1.4 mm, glabrate. Leaves often sub opposite or opposite distally, mostly alternate proximally; petiole (1-)5-12(-20) mm, glabrous (sparsely short-pubescent) ; blade obovate to narrowly oblong (elliptical, oblanceolate, broadly obovate), (3-)5-10(-11.5) × (1.4-)2.3-4.9(-5.7) cm; base convex to cuneate (seldom to rounded) ; apex irregularly rounded to emarginate (rounded-obtuse, very rarely cuspidate) ; margins entire to minutely toothed, often somewhat revolute, with 1 to several glands at base or along whole leaf margin; abaxial surface glabrous or glabrate, drying pale to medium brown (rarely greenish) ; adaxial surface glabrous or glabrate, drying darker brown. Inflorescences racemes (or pseudoracemes, with bracteoles often borne in the middle of the pedicels ; rarely in part racemiform panicles with few 2-flowered branches), lateral, 4–9.5 cm, moderately short-pubescent to glabrous proximally, to densely or patchily pubescent distally; peduncle 1.5–5 cm, slender; pedicel (1-)1.5-5(-7) mm, densely short-pubescent ; bracts broadly oblong to broadly ovate or suborbicular, (0.5-)1-2 mm, moderately to densely pubescent (seldom to glabrate) ; bracteoles ovate (deltoid, oblong), (0.4-)1-1.5(-2.5) mm, pubescent (to glabrate). Flowers: sepals greenish to yellowish or whitish, 4(to 5), broadly oblong to broad-based obovate or oblong (rarely broadly elliptical) with a rounded apex, 3-5.5(-6.5) mm, abaxial surface densely (to moderately above) short-pubescent ; calyx cup funnelform, densely short-pubescent ; sepal glands yellow, roughly rectangular, 1-1.5 × 0.5-0.6 mm, upper surface glabrous ; petals cream to white, greenish, yellowish or pinkish-white (to pinkish after flowering), obovate with a narrow base, irregularly rounded apex, 3.6-6.2 × 2.6-3.8 mm, normally longer than sepals (similar in length in abnormal, possibly immature flowers), abaxial surface densely pubescent especially towards base, adaxial surface glabrous ; filaments 2-2.5(-3) mm, glabrous ; anthers orange to yellow, 0.4– 0.5 mm ; ovary shallowly conical to flat (becoming hemispherical), hispid (villous) ; styles 3-4(-5), 1.5–2 mm, basally hispid (villous). Seeds 1 per fruit, subglobose, to at least 3 mm.
Vernacular names and uses. — “Hagontoho mainty” (Réserves Naturelles 2470) ; “Hazoambo” (Raharimalala 169, Service Forestier 5621, 5642, 9513, 10174, 13687, 19951); “Hazombaribe” (Réserves Naturelles 7973); “Hazombato” (Raharimalala 332, Réserves Naturelles 8034) ; Hazomby Ludovic et al. 560 “Hazonjia” (Service Forestier 5036); “Maimbo lambo” (Bernard 261, Raharimalala 279); “Malitsy anjahana” (Réserves Naturelles 4939) ; “Ramisaona” (Service Forestier 4902, 13687); “Ranjombitro” (Service Forestier 7093); “Rotramena-beravina” (Service Forestier 7349) ; “Tsitakonala” [Bm dialect] “Tsilaiha” (Réserves Naturelles 4547) ; “Tsitakonala” (Louvel 35,199, Service Forestier 5734, 10052, 10070); “Tsitakotrala” (Rabenantoandro et al. 820); “Voatoala” (Cours 2978).
The wood of H. laxiflorum is used for construction (Service Forestier 19001).
Distribution, ecology and conservation status. — Homalium laxiflorum occurs primarily in littoral and sublittoral forests on sand, less often in low-elevation humid forest, occasionally on laterite. One collection from 671 m altitude (see below) is from the massif of Ankirindro, where a number of normally littoral species are reported to occur, possibly because the weathered quartzite sand substrate is similar to that of nearby littoral forests (G. Schatz, pers. comm.).The species is widely distributed, with recent collections demonstrating its presence in three provinces, and relatively common; therefore, despite ongoing threats to the remaining littoral forest, its preliminary assessment of conservation status should probably be “Least Concern” [LC],
Notes. — Sleumer (1973) designated “Aubert du Petit Thouars P & P-Juss 14412” as lectotype of H. laxiflorum ; since this refers to at least two different sheets, one of them in the main herbarium collection at P, second-stage lectotypification is necessary. Only an inadequate image of the sheet in the Jussieu collection was available ; it appears to contain material of rather poor quality, poorly labeled, and possibly heterogeneous. The sheet in the main collection at P is both better and more accessible, and is therefore preferred over the P-Juss sheet. In addition, Sleumer marked as “syn- & lectotype” a sheet from Herbarium Richard [P04705842], labeled “Myrianthea”, “Madagascar” and, almost illegibly, “DupetitTh”. It may not be totally certain that this sheet represents the same collection; if it does, it is also inferior to the selected sheet. Sleumer stated that the type was from Foulpointe. None of the specimen labels provide locality data, but it is known that Petit-Thouars collected only around Fort-Dauphin (where H. laxiflorum does not occur) and on the “[east] coast near Fenerive” (Dorr, 1997: 346), which would make Foulpointe a likely locality.
Homalium laxiflorum is the most frequently collected species in the section and is usually quite cohesive. Schatz et al 3921, the collection from the mid-elevation quartzite massif of Ankirindro, has unusually large flowers and small, broad leaves with very short petioles (1–2 mm long, vs. at least 2.5 mm in all other specimens seen).This may represent environmentally induced variation or a genetically distinct variety, for which there is not sufficient material to permit formal description.
Additional material examined. — Madagascar. Prov.Antsiranana: Fkt. Antanandava (Anjia), 15°17′14″S 50°20′12″E, 25.II.2001, fl.,Antilahimena et al. 705 (MO); road between Sanjahana and Ambinaniny Mahorambo, 15°13′25″S 50°26′36″E, 8.VI.2001, fl.,Antilahimena et al. 746 (MO); Masoala, Fkt. Sahamalaza, Vinanivao, 15°52′S 50°19′E, 0–113 m, 12.XII.1995,fl., Aridy et al. 13 (MO,P) ; ibid. loc., 15°49′S 50°18′E, 0–41 m, 22.II.1996, fl.,Aridy & Moïse 170 (G, MO, P) ; ibid. loc., same date,Aridy & Moïse 171 (MO, P) ; Masoala, forêt d'Ambodipont, 15°44′45″S 50°19′25″E, 0–10 m, 15–20. III.1996, fl., Bernard 261 (MO,P); ibid. loc., 3.X.1996, fl., Bernard 368 (G, MO,P) ; Fampotatrely, Antalaha, Parc Masoala, 15°35′S 50°25′E, 0–50 m, 12.V.1996, post-fl., Bernard 291 (MO,P) ; entre Antalaha et Sambava, côte NE, XI.1912, fl., Perrier de la Bâthie 6696 (P) ; Masoala, Antsiraminanana, 15°28′S 50°26′E, 27.IX.1994, Rahajasoa et al. 631 (P) ; Fkt. Sahafary, forêt d'Antsoha, 15°16′12″S 50°23′14″E, 50 m, 1.X.1997, fl., Ravololonanahary 111 (G, K, MO) ; Fkt. Ambodirafia, 15°16′S 50°28′E, 23 m, 18.III.2001, fl., Razakamalala et al. 79 (MO,P); 1.5 km W of Cap Est, 15°16′28″S 50°27′51″E, 35 m, 24.I.1999, fl., Schatz et al. 3802 (G, MO, P) ; env. W d'Ambodipont-Isahana, entre Sambava et Antalaha, 17.IV.1967, fl., Service Forestier 27718 (P). Prov. Fianarantsoa: forêt d'Ambahy, 20°45′44″S 48°29′20″E,22 m, 31.I.2012, fl., Andriamihajarivo & Ravoahangy 1848 (MO) ; env. de Farafangana, XII.1963, fl., Bosser 18691 (MO,P) ; Mananjary, 21.XI.1908, fl., Decary 13784 (P) ; Mananjary, III-IV.1909, fl., Geay 7260 (P) ; ibid. loc., same date, fl., Geay 7393 (P) ; ibid. loc., same date, fl., Geay 7400 (P) ; ibid. loc., same date, fl., Geay 7412 (P) ; ibid. loc., same date, fl., Geay 7568 (P) ; ibid. loc., same date, st., Geay 7857 (P) ; ibid. loc., same date, fl., Geay 8025 (P) ; Bassin inférieur du Faraony, côte est, X.1911, fl., Perrier de la Bâthie 6695(P) ; N de Mahanoro, X.1921, fl., Perrier de la Bâthie 14521 (P) ; Fkt. Ambalavontaka, forêt d'Antaimby, 20°22′22″S 48°33′16″E, 10 m, 16.IV.2004, fl., Razakamalala et al. 1109 (MO, P) ; Fkt. Ampasimaneva, forêt d'Ambolo, 20°43′59″S 48°27′09″E, 13 m, 15.VI.2004, Razakamalala et al. 1473 (MO) ; Fkt. Marohita, forêt d'Alimamba, 21°28′04″S 48°17′43″E, 13 m,X.2004, fl., Razakamalala et al. 1606 (MO, P) ; Distr. de Mahanoro, Iambola[?] , 14. III.1952, fl., Service Forestier 4902 (P) ; Mananjary, Manampona, 7.I.1953, fl., Service Forestier 5621 (P) ; Mananjary, Sakarivo, 23.III.1952, buds, Service Forestier 5642 (P) ; Vohipeno, Analalava, 15.XII.1952, fl., Service Forestier 7093 (P) ; Pangalane, S Mananjary, 24.II.1954, fl., Service Forestier 9513 (P) ; Mananjary, Befoza, 25.III.1954, buds, Service Forestier 10174 (MO,P) ; Mananjary, Ampangalana-Nord, 26.II.1955, fl., Service Forestier 13687 (P) ; Nosy Varika, Ambohitsara I, forêt d'Analalava, 31.III.1961, fl., Service Forestier 19951 (P). Prov. Mahajanga : Ankatsaka, 3.V.1952, fl., Service Forestier 5036 (P). Prov. Toamasina : Betampona, piste principale, 17°55′S 49°13′E, 210–410 m, 25.IV.1994, fl., Andrianarisata 137 (MO,P) ; forêt d'Analalava près de Foulpointe, 17°43′19″S 49°28′11″E, 250 m, 30.X.2000, fl.,Andrianjafy & Rakotoarisoa 136 (P) ; Fkt. Anamborano, près rivière Ihazoarina, à 10 km au N d'Anamborano, 17°42′04″S 49°00′48″E, 620 m, 12.VI.2004, fl.,Andrianjafy et al. 441 (MO,P) ; Fkt. Marovovonana, Ankirindro forest, 15°17′24″S 49°32′51″E, 584 m, 11.I.2003, fl. and post-fl.,Antilahimena et al. 1693 (MO, P) ; Foulpointe,X.1962, post-fl., Bosser 16993 (MO,P [2 sheets]) ; Voie ferrée en allant de Tamatave, 13.X.1946, post-fl., Cours 2978 (MO,P) ; road to Analalava, W of Foulpointe, 7.XII.1984, fl., Dorr & Barnett 3320 (P) ; Passimbol [Ampasimbola, 21.VIII.1881], fl., Humblot 34 (P) ; Foulpointe [18. XII.1881], fl., Humblot 87 (P) ; Antsianaka [17.XII.1882], st., Humblot 520 (P) ; Andranokoditra, forêt de Vohibola, 18°34′26″S 49°14′36″E, 17 m, 14.XII.2004, fl., Lehavana et al. 231 (MO,P) ; Tampina, XI.1925, post-fl., Louvel 35 (P) ; Ambalahasina, forêt de Vohibola partie W, 18°32′S 49°14′E, 3–10 m, 26.X.2002, Ludovic 187 (MO) ; Fkt. Andranokoditra, forêt de Vohibola (partie S), piste Ambodinanto, 18°34′20–53″S 49°14′42–54″E, 53 m, 7.I.2013, fl., Ludovic & Rakotoarivony 236 (P) ; Fkt. Ambalavontaka, forêt d'Antaimby à 2.5 km au S d'Ambalavontaka, 20°22′58″S 48°33′14″E, 10 m, 13.II.2004, fl., Ludovic et al. 560 (MO) ; Manompana, rivière Antsohy, 16°46′11″S 49°42′04″E, 8m, 25.IX.2010, fl, Manjato et al. 251 (MO,P) ; Near village of Antanambao-Ambodimanga, 16°45′39″S 49°42′29″E, 10 m, 19.V.2003, fl., McPherson et al. 18937 (MO,P) ; Foulpointe, forêt d'Andranampango, 17°41′02″S 49°30′32″E, 12.I.2013, fl.,Miandrimanana et al. 579 (G,MO) ; Foulpointe, 22.XII.1995, fl., Pauly 756 (P) ; Mahambo, distr. Fénérive, 12.VIII.1961, st., Peltier & Peltier 3422 (P) ; Fkt. Andranokoditra, forêt CBD à Vohibola, 18°34′50″S 49°15′16″E, 10 m, 8.XII.2001, fl., Rabenantoandro et al. 820 (MO, P) ; Fkt. Rantabe, 15°43′48″S 49°39′21″E, 5 m, 19. II.2002, fl., Rabenantoandro et al. 890 (MO, P) ; Fkt. Andranokoditra, forêtc côté de l'hôtel Pangalane, 18°35′32″S 49°14′02″E, 5 m, 11. II.2003, fl., Rabenantoandro et al. 1219 (MO, P) ; Ankanin'ny nofy, forêt de Vohibola, 18°35′42″S 49°14′02″E, 10.II.2003,fl., Rabevohitra et al. 4388 (MO, P) ; Mananara-Nord, sur sentier vers pk. 5 avant l'entrepôt Trans 7, 30.I.1990,post-fl., Raharimalala 169 (P) ; Mananara-Nord, forêt de Beharamy (fkt. Sarahandrano), 12.II.1990, fl., Raharimalala 279 (P) ; Mananara-Nord, sur sentier pk. 5 à droite avant de passer d'entrepôt Trans 7, 27.II.1990, post-fl., Raharimalala 332 (P) ; Tanambao-Ambodimanga, forêt de Menagisa-Pointalare [Pointe à Larrée], à 3 km vol d'oiseau au S de Tanambao Forêt, 16°46′35″S 49°41′20″E, 26 m, 9.IV.2011, fl., Randrianaivo et al. 1827 (MO, P) ; Fénérive-Est,Tampolo Station Forestière, 17°17′00″S 49°23′30″E, 10 m, 29.VI.1995, fl., Razafimandimbison 149 (MO, P) ; ibid. loc., 17°17′20″S 49°25′37″ E, 10 m, 30.VI.2001, fl., Razakamalala et al. 149 (MO) ; Fkt. Ambalavontaka, forêt d'Antaimby, 20°22′21″S 48°33′15″E, 13 m,X.2004, buds, Razakamalala et al. 1579 (P) ;Tampina,X.1924, fl., Réserves Naturelles (Dumazer) s.n. (P) ; Distr. Tamatave, Ambatomanahafo, 11.III.1950, fl., Réserves Naturelles 2470 (P) ; R.N. I [Betampona], 30.XI.1951, post-fl., Réserves Naturelles 3401 (P) ; ibid. loc., 22.XII.1952, fl., Réserves Naturelles 4547 (P [2 sheets]) ; R.N. II [Masoala], canton Ambohitralanana, 24.I.1953, post-fl., Réserves Naturelles 4939 (P) ; Ambohitralanana, 19.XII.1956, post-fl., Réserves Naturelles 7973 (P) ; Ambodiriana, 9.XII.1956, fl., Réserves Naturelles 8034 (P) ; summit of massif of Ankirindro, ca. 25 air-km NW of Maroantsetra via the Antainambalana and Vohimaro rivers, 15°18′08″S 49°33′04″ W, 671 m, 1.II.1999, fl., Schatz et al. 3921 (G, MO, P) ; Ambila - Brickaville, 27.I.1951, fl., Service Forestier 1126 (P) ; Ambila-Lemaitso, s.d., fl., Service Forestier 2105 (P) ; ibid. loc., 22.I.1951, fl., Service Forestier 2990 (P) ; ibid. loc., 17.IV.1951, post-fl., Service Forestier 3257 (P) ; Ampanotoamazina, Ambila-Lemaitso, 14.VII.1952, fl., Service Forestier 5734 (P) ; Ambila-Lemaitso, 17.XII.1952, Service Forestier 6456 (P) ; Ambatomanasy [?], Maroantsetra, 16.XII.1952, fl., Service Forestier 7349 (P) ; Bassin de la Mahalevona, massif d'Ansirosiro aux env. de [Fizoana], 400 m, date illeg., fl., Service Forestier 8733 (P) ; JB-21 Tampolo, 10.IV.1954, fl., Service Forestier 10052 (MO, P) ; forêt de Tampolo, 15.IV.1954, fl., Service Forestier 10070 (P) ; Tampolo, 7.XII.1954, fl., Service Forestier 12487 (P) ; Ambila-Lemaitso, sous parcelle F2K, 20.II.1958, fl., Service Forestier 19001 (P) ; forêt de Mangalimaso à l'W de Foulpointe, 23.XI.1962, fl., Service Forestier 22089 (P) ; env. de Chutes de la Mort (P.K. 51 de la route Moramanga-Anosibe), 11.XII.1965, post-fl., Service Forestier 24388 (P) ; Pangalanes Est, à la virge du lac Ampitabe, 15.I.1967, fl., Service Forestier 26234 (P) ; Chaîne de collines d'Ankirihiry, à l'W d'Antetezana (S de Foulpointe), 23. V. 1969, fl., Service Forestier 28888 (P [2 sheets]). Prov. unkown : sine loc., s.d., fl., Baron 5948 (P) ; forêts côtières de l'E, s.d., fl., Louvel 199 (P).
7.Homalium maringitra H. Perrier in Mém. Mus. Natl. Hist. Nat. 13 : 298. 1940.
Lectotypus (first step, designated by Sleumer, 1973 : 319) : Madagascar. Prov. Toamasina : Analamazaotra, 800 m, I.19??, fl., Perrier de la Bâthie 6725 (P ; isolecto- : BM, K).
Lectotypus (second step, designated here) : Madagas-CAR.Prov. Toamasina : Analamazaotra,800 m, I.19??, fl., Perrier de la Bâthie 6725 (P [P00624063]! ; isolecto- : P [P00624062]!, BM, K [K000231475] image seen, PRE [PRE0297346-0] image seen, S [S-G-3252] image seen, TAN [TAN000244] image seen, US [US00114727] image seen). Syntypus : Madagascar. Prov. Toamasina : forêts montagneuses de l'Est, s.d., fl., Louvel 250 (P [P00624061]!).
Tree to 25 m tall, 28 cm dbh ; large twigs grayish (to brown) ; young twigs dark brown, glabrous ; stipules deltoid to lanceolate, 0.6–1.5 mm, glabrous to minutely pubescent. Leaves alternate ; petiole (2-)3-5.5(-8) mm, glabrous ; blade elliptical (narrowly elliptical to oblong-elliptical, obovate), (2-)3.6-5.3(-7.5) × (1.4-)1.8-3.3(-3.7) cm ; base rounded to convex (cuneate, basally attenuate) ; apex round, occasionally emarginate (acute to obtuse with rounded tip) ; margins bearing several small teeth per side (or shallowly wavy) with small glands ; abaxial surface glabrous, drying olive to medium brown ; adaxial surface glabrous, drying usually paler, grayish or gray-green to tan (dark brown). Inflorescences racemes or narrow racemiform panicles with short 2-flowered branches, lateral, (3.2-)4.3-7.8(-12) cm, minutely pubescent (to glabrous proximally) ; peduncle (0.6-)1.4-4(8.5) cm, slender and somewhat flat ; pedicel (0.5-)1.5-5(-6) mm, short-pubescent ; bracts ovate to broadly deltoid, 0.6-1(-1.5) mm, glabrous to short-pubescent ; bracteoles ovate to broadly deltoid, 0.3-0.6(-1) mm, glabrous to short-pubescent. Flowers : sepals green to pinkish or yellowish green, 4–5, ovate to oblongovate (somewhat elliptical to narrowly elliptical, narrowly oblong) with rounded (acute) apex, 2–3.5 mm, abaxial surface sparsely short-pubescent to glabrous ; calyx cup funnelform, sparsely short-pubesecent to glabrate ; sepal glands orange or yellow, semicircular to irregularly rectangular, (0.6-)0.8-1.4 × (0.4-)0.5-0.7 mm, short-pubescent above and sometimes beneath ; petals white to greenish, yellowish green, white with pink spots, or yellowish pink, elliptical to obovate or narrowly obovate with a short narrow base, rounded (acute) apex, 3.6-6 ×1.5-2.8 mm, often almost twice as long as sepals, abaxial surface short appressed-pubescent (to glabrous at margins), adaxial surface glabrous (rarely sparsely pubescent towards base) ; filaments 1.5–2.5 mm, glabrous ; anthers yellow, 0.4– 0.5 mm ; ovary nearly flat, appressed-pubescent ; styles 4, 0.7–2.5 mm, basally appressed-pubescent. Seeds not seen.
Vernacular names. — “Ampitsikahitra” (Louvel 250); “Hazomalany” (Antilahimena & Razafindasy 3500) ; “Maringitra” (Perrier de la Bâthie 6725).
Distribution, ecology and conservation status. — Homalium maringitra is found in mid-elevation humid forests ; it is reported to occur on laterite. The species is only known from two small, well-separated regions, with less than five clearly distinct locations. Most collections have been made from the eastern site of Ambatovy near a mining project, extending to the nearby southern end of the Mantadia national park ; two others have come from the much more northerly reserve of Anjanaharibe-Sud. The first-mentioned location is obviously threatened by human activity, and the species' area of occupancy is, as a consequence of the number of collections, less than 500 km2. Hence, a preliminary assessment of conservation status as “Endangered” [EN B2ab(iii)] would be appropriate.
Notes. — Sleumer (1973) designated Perrier de la Bâthie 6725 as lectotype and marked both sheets held at P as “Syn & Lectotype” with no indication of preference between them. Art.9.17 of the ICN (McNeill et al., 2012) recommends that a second-stage lectotypification be published ; the sheet with better inflorescences is herein selected.
Homalium maringitra is notable for its small elliptical leaves and small flowers with short, sparsely pubescent to glabrous sepals yet densely pubescent sepal glands. It is believed to form a natural group with the newly described rare species H. dorrii and H. ranomafanicum.The former has often narrowly obovate leaves and longer sepals, both absolutely and relative to the petals, and is found in low-elevation forest on laterite, while the latter has often broadly obovate leaves, with revolute to subentire margins and few glands, and long paniculate inflorescences and is found in southeastern mid-elevation forest.
Additional material examined. - . Prov. Mahajanga: Anjanaharibe-Sud, Anjiamazava, suivant la route Nationale d'Andapa-Bealanana, piste vers le N approchant le sommet de Bevitsika, 14°42′S 49°27′E, 1100 m, 14.XII.1994, fl., Ravelonarivo & Rabesonina 560 (G, MO, P) ; Manandriana, versant W d'Anjanaharibe-Sud RS, forêt d'Anjiamazava, 14°48′S 49°27′E, 961 m, 3–7.II.1997, fl., Ravelonarivo et al. 1064 (G, K, MO). Prov. Toamasina : Fkt. Menalamba, Ambatovy, forêt d'Analamay, 18°49′27″S 48°20′13″E, s.d., fl., Andriatsiferana 2549 (MO) ; Fkt. Menalamba, Ambatovy forest up to Berano village, 18°50′13″S 48°19′19″E, 1130 m, 17.I.2005, fl.,Antilahimena et al. 3202 (MO, P) ; Fkt. Berano, Ambatovy forest, 18°49′14″S 48°20′07″E, 1120 m, 3.II.2005, buds,Antilahimena et al. 3278 (P) ; ibid. loc., 18°49′19″S 48°20′08″E, 1094 m, same date, fl.,Antilahimena et al. 3297 (MO, P) ; ibid. loc., 18°48′33″S 48°19′22″E, 1074 m, 17.II.2005, fl., Antilahimena et al. 3420 (MO, P) ; ibid. loc., Analamay, 18°51′36″S 48°18′03″E, 1134 m, 1.III.2005, post-ft., Antilahimena & Razafindasy 3500 (MO, P) ; ibid. loc., Ampangadiantrandraka forest, 18°51′45″S 48°17′44″E, 1035 m, 4.III.2005, fl., Antilahimena & Félix 3579 (P) ; Fkt. Menalamba, Ambatovy forest, 18°50′22″S 48°18′47″E, 1142 m, 24.I.2007, fl., Antilahimena et al. 5205 (P) ; Fkt. Falierana, Mantadia, S boundary of Mantady forest, 18°53′22″S 48°26′53″E,997 m, 14.XII.2013, fl., Antilahimena et al. 8792 (P) ; Andasibe, forêt de Maromizaha, 18°57′56″S 48°27′34″E, 1020 m, 1.IV.1999, fl., Labat et al. 3069 (MO, P) ; Ambatovy, nickel-mining exploration site, plot 18 of Golder map, 18°51′12″S 48°18′48″E, 1100 m, 26.II.1998, fl., McPherson 17471 (MO) ; Phelps Dodge project site, Ambatovy, SE valley, contour line PDM-Pit-8,18°51′24″S 48°17′41″E, 1000 m, 6.III.1997,fl., Rakotomalaza et al. 1242 (MO, P) ; Ambatovy, 18°51′33″S 48°17′40″E, 990 m, 25.III.1997, fl., Rakotomalaza et al. 1275 (MO) ; Fkt. Ampitambe, Ambatovy, env. 22 km NE de Moramaga, 18°51′24″S 48°18′39″E, 1082 m, 3.III.2005, fl., Rakotovao et al. 1466 (MO, P) ; Fkt. Menalamba, 11 km E d'Ampitambe, Ambatovy, 18°49′26″S 48°20′02″E, 1081 m, 31.III.2005, fl., Rakotovao et al. 1694 (MO, P) ; ibid. loc., 18°49′14″S 48°19′27″E, 1114 m, 4.IV.2005, fl., Rakotovao & Edmond 1766 (MO, P) ; Fkt. Ampitabe, Ambatovy, coté W de la route vers Andranovery, 18°51′37″S 48°18′02″E, 1107 m, 21.V.2008, fl., Rakotovao 4056 (MO, P) ; Fkt. Ampitambe, piste direction S du campement Dynatec, 18°51′26″S 48°18′12″ E, 1080 m, 18.I.2005, fl., Ranaivojaona et al. 1133 (MO, P) ; Analamazaotra, Amboasary, 18°57′07″S 48°25′53″E, 1040 m, 18.XII.2013, fl., Rasoazanany et al. 559 (MO, P) ; Mantadia, boucle chute sacrée - Rinasoa, 18°49′48″S 48°26′25″E, 1074 m, 19.XII.2013, fl., Rasoazanany et al. 566 (P) ; Fkt. Menalamba, forêt d'Ampangadiatrandraka, 18°51′15″S 48°17′52″E, 1110 m, 8.XII.2006, fl., Razanatsoa & Marcellin 255 (MO, P).
8.Homalium nobile Baill. in Bull. Mens. Soc. Linn. Paris 1 : 575. 1889.
Lectotypus (designated by Sleumer, 1973: 325) : Madagascar.Prov. Toamasina : Ampasimbola, 21. VIII.1881, fl., Humblot 33 (P [P04734254]! ; isolecto- : W). Syntypus : Madagascar. Prov. Toamasina : Antsianaka, 5.III.1883, fl., Humblot 659 (K [K000231464, K000231466, K000231467] images seen, P [P04734255, P04734274]!, TAN [TAN000594] image seen, W).
Tree to 16 m tall, 20 cm dbh ; large twigs dark brown to greenish- or grayish-brown ; young twigs dark brown to grayish- or red-brown, sparsely to moderately short-pubes-cent when young ; stipules narrowly lanceolate to linear, 2– 3.3 mm, short-pubescent. Leaves alternate (rarely subopposite) ; petiole 7–23 mm, sparsely short-pubescent (sometimes becoming glabrous) ; blade elliptical to obovate (broadly obovate), (5.5-)6.5-18 × (3-)4-9 cm ; base convex (rarely to rounded or cuneate) ; apex rounded to emarginate (shallowly cuspidate) ; margins entire to slightly revolute (very slightly repand) with 1–5 glands in margins towards base, usually not forming teeth ; abaxial surface short-pubescent on midrib (sparsely and inconspicuously pubescent throughout), drying brown to dark brown (olive-tinged) ; adaxial surface glabrous, drying brown to dark brown (olive-tinged). Inflorescences racemose, lateral (usually not clustered near apices), (1.5-) 2.3-10(-13.5) cm, densely to moderately short-pubescent ; peduncle (0.2-)0.5-4 cm, thick ; pedicel 1–5 mm, densely pubescent ; bracts broadly ovate, 1.5–2.3 mm, moderately to densely pubescent ; bracteoles ovate to lanceolate, 1–2.5 mm (unequal), densely pubescent. Flowers : sepals 5, greenish-white to yellowish-green, lanceolate-oblong to elliptical (obovate) with acute (to obtuse or rounded) apex, 5–8.4 mm, abaxial surface densely pubescent to sericeous (to moderately so near margins), with a shallow keel usually visible for over half of length ; calyx cup funnelform, densely sericeous ; sepal glands yellow, irregularly shaped, 1.2-1.4 × 0.7-0.8 mm, upper surface glabrous and wrinkled ; petals white to greenish white, obovate to broadly obovate with a narrowed base, round (to rounded-obtuse) apex, 5.5-9 × 3.4-5 mm, slightly longer than sepals, abaxial surface densely sericeous especially along central axis but not prominently keeled, adaxial surface glabrous (sparsely pubescent) ; filaments white, 2.5–4 mm, glabrous ; anthers yellow to brown, 0.5 mm ; ovary roundedconic, pilose ; styles 3–4, 3–4 mm, pilose to sericeous at base or for much of length. Seeds possibly 4 or more per fruit (only very young fruit seen).
Vernacular names and uses. — “Fotsiavadika” (Réserves Naturelles 8731) ; “Hazomborondreo” (Service Forestier 1370) ; “Mahitsiantjaha” (Service Forestier 21516) ; “Tsitakonala à g.f. [grands feuilles]” (Service Forestier 15218).
The wood of Homalium nobile is used for construction (Service Forestier 21516).
Homalium nobile is usually native to littoral or low-elevation humid forests, but Antsianaka, the reported location of Humblot 659, is believed to be a locality near Lac Alaotra, well inland at moderate elevation. No more than 10 distinct locations are known, and the littoral forest is fragmented and, outside protected areas, faces continuing loss ; hence a preliminary conservation status assessment of “Vulnerable” [VU B2ab(iii)] is appropriate.
Notes. — Sleumer (1973 : 325) designated Humblot 33 as lectotype ; the collection number was given as 333 by typographical error. The label of the sheet at P does not specify a locality or date, but Humblot's field book records that this specimen was collected at “Passimbol” on 21 August 1881. Sleumer gave the type locality as “Nosy Varika, Befotaka, ‘Passimbal’ = Ampasimbola”, but this appears to be an error based on the assumption that Passimbal must have referred to the only well-known locality named Ampasimbola (located at 19°49′S 48°22′E).That locality is well inland at an unusually high altitude for H. nobile (ca. 500 m), and, given the roads of the time, it was an inconveniently long distance away from other sites at which Humblot collected around the same time. On 19 August 1881 and 25 August respectively, Humblot made collections at Foulpointe and “Ambatmalam”, which a later annotation to the field books suggests may have been a locality north of Foulpointe. The same annotator suggested that Passimbol was an Ampasimbola located south of Andevoranto (18°55′S 49°08′E) on the east coast, which is not shown on the relatively modern official maps of Madagascar. However, those maps do indicate the existence of an Ampasimbola next to Andondabe (17°45′S 49°22′E), which is only 22 km southwest of Foulpointe [Mahavelona]. This, or someplace nearby, is probably the locality most likely to have been the source of the type collection (and of Humblot 34, a specimen of H. laxiflorum).
Homalium nobile belongs to the apparently cohesive group of species of eastern littoral or low-elevation forests with racemose inflorescences and pubescent perianths, within which it is distinctive for its sometimes quite large leaves. It is noted above to be most similar to H. brevipedunculatum, which has leaves of a smaller maximum size, normally short inflorescences, and oblanceolate to narrowly obovate petals. The distribution of the two overlaps in Fianarantsoa, and one apparent hybrid specimen is known. The widespread H. laxiflorum also has moderate-sized leaves and smaller flowers ; it is distinguished from both H. nobile and H. brevifolium in that the sepals are usually 4 in number, oblong to broad-based obovate with a rounded apex ; in normal individuals the petals are substantially longer than the sepals ; and the petal indument, though usually dense, is not exceptionally long as in the other two species. The inflorescences of both H. nobile and H. brevipedunculatum are often densely pubescent throughout, though that is not entirely consistent, whereas the inflorescence of H. laxiflorum is typically less pubescent on the proximal portion.
Additional material examined. — Madagascar. Prov. Antsiranana : Sahamalaza-Anovandrano, Masoala, 15°18′45″S 50°20′30″E, 75–150 m, 24.XI.1995, Bernard 145 (MO, P) ; Distr. Antalaha, canton Ambohitralalana, 15.I.1957, fr., Réserves Naturelles 8731 (P) ; Masoala, inside park boundary 2 km W of Cap Est, 15°16′23″S 50°27′24″E, 5 m, 23.I.1999, fl., Schatz et al. 3768 (MO, P). Prov. Fianarantsoa : forêt de Mahabo, 23°10″39″S 47°43′06″E, 10 m,25.IX.2002, fl., Rabenantoandro et al. 1002 (MO) ; Trail to Analamena, 23°10′45″S 47°42′58″E, 28 m, 8.XI.2004, fl., Randrianasolo et al. 885 (MO) ; Mahabo, 23°10′39″S 47°42′24″E, 14 m, 11.XI.2002, fl., Razakamalala & Ludovic 333 (MO). Prov. Toamasina : Ambila au S de Tamatave, 10.V.1928, fl., Decary 6494 (P) ; Station Forestier de Tampolo, 10 km N of Fénérive, 29.XI.1985, fr., Dorr 4396 (P) ; forêt de Tampolo, près du village Tanambao-Tampolo, 17°17′S 49″25′E, 0–5 m, 5–15.IV.1997, fl., Ralimanana et al. 85 (MO) ; Ambila-Lemaitso, forest along road from Brickaville a few km before ferry place, 18°49′S 49°08′E, 0–5 m, 11.XI.1999, Randrianasolo & Ranaivojaona 646 (MO, P) ; Andatsakala, 10.V.1950, fl., Service Forestier 1370 (P) ; env. de la baie d'Antongil, Anondrivala, au S de Rantabe, I.1954, fl., Service Forestier 8935 (P [4 sheets]) ; Tampolo, 9.XII.1955, fr., Service Forestier 15218 (P) ; Mahambo, au S de Fénérive, 30.VIII.1957, fl., Service Forestier 18140 (P) ; Manambia, Marosoroka, 30.XI.1963, fl., fr., Service Forestier 21516 (MO, P).
9. Homalium oppositifolium (Tul.) Baill. in Bull. Mens. Soc. Linn. Paris 1 : 575. 1889.
≡Myriantheia oppositifolia Tul. in Ann. Sci. Nat., Bot. sér. 4, 8 : 65. 1857 [as Myrianthea].
Typus : Madagascar : sine loc., s.d., fl., du Petit-Jhouars s.n. (P [P04705657]! ; iso- : P [P04705659]!)
≡Homalium fasciculatum Scott-Elliot in J. Linn. Soc., Bot. 29 : 21. 1891. Lectotypus (designated by Sleumer, 1973 : 323) : Madagascar. Prov. Toliara : Fort-Dauphin, V.18??, fl., Scott Elliot 2617 (K [K000231470] image seen ; isolecto-, PRE [PRE0602205-0] image seen). Syntypus : Madagascar. Prov. Toliara : Fort-Dauphin, V.18??, post-fl., Scott Elliot 2639 (K [K000231471] image seen, P [P04705656]!).
≡ Homalium lanceolatum Scott-Elliot in J. Linn. Soc., Bot. 29 : 23. 1891. Typus : Madagascar. Prov. Toliara : Fort-Dauphin, s.d., fl., Scott Elliot 3056 (holo- : K [K000231472] image seen ; iso-, P [P04705661]!, L [L0010982] image seen).
≡ Homalium cymosulum Scott-Elliot in J. Linn. Soc., Bot. 29 : 22. 1891. Typus : Madagascar. Prov. Toliara : Fort-Dauphin, VII.18??, fl., Scott Elliot 3037 (holo- : K [K000231469] image seen ; iso- : P [P04705658]!) [Hybrid of H. oppositifolium × H. trigynum].
Tree to 20 m tall, 40(-80) cm dbh, with smooth whitish bark ; large twigs grayish to brown ; young twigs brown to tan, short-pubescent to glabrous ; stipules linear to narrowly deltoid or narrowly lanceolate, (1-)1.5-3 mm, shortpubescent. Leaves mostly opposite ; petiole 2-6(-10) mm, short-pubescent (especially when young) to glabrous ; blade elliptical to broadly elliptical (narrowly elliptical or oblongelliptical, obovate, very rarely oblanceolate), 4.2-7.2(-9.5) × 1.8-3.5(-5) cm ; base rounded to convex (cuneate, probably only when young) ; apex rounded (to apiculate, short-attenuate, emarginate, obtuse to acute) ; margins serrulate at least basally (to subentire), often somewhat revolute, with glands usually borne in small teeth, sometimes absent or only 2 or 3 ; abaxial surface short-pubescent on midrib (seldom on other veins or surface), often becoming glabrous, drying brown ; adaxial surface glabrous (short-pubescent along midrib), drying darker brown than abaxial surface. Inflorescences racemose with flowers often opposite or clustered, lateral, (1.5-)4-10(-14) cm, densely (moderately) short-pubescent (rarely glabrate distally) ; peduncle 0.3–3 cm, moderately thick ; pedicel 1-4(-6.5) mm, densely pubescent with crinkly hair ; bracts occasionally numerous on lower part of rachis, ovate to elliptical, lanceolate or oblong (broadly ovate to broadly oblong), (1-)1.7-3(-4.5) mm, usually densely pubescent ; bracteoles lanceolate to oblong-elliptical, 1-3(-4.4) mm, usually densely pubescent. Flowers : sepals 5–6, white to pale or yellowish green, oblong-ovate to narrowly elliptical or elliptical, narrowly oblong-elliptical, or oblanceolate with rounded to acute apex, (2.6-)3-6 mm, abaxial surface pubescent with appressed and protruding crinkly hairs, less so near apical margin, adaxial surface also sometimes sparsely pubescent; calyx cup funnelform (sometimes to cup-shaped or cylindrical), pubescent ; sepal glands yellow (ringed with orange, or with dark guides), broadly elliptical (oblong), sometimes prominently elevated on pubescent stalk, 0.6-1 (-1.4) × 0.4-0.7 mm, upper surface short-pubescent (sometimes minutely or only in the center) ; petals white, obovate (oblanceolate) with rounded apex, (3-)3.4-7.3 × 1.3-2.8 mm, moderately longer than sepals, abaxial surface densely to moderately, mostly appressed long-pubescent (less pubescent along apical margins), adaxial surface sparsely pubescent or glabrous ; stamens normally 3 per fascicle (aberrantly in part 4 per fascicle) ; filaments white or pale pink, 2.4–4 mm, glabrous or sparsely villous ; anthers red to reddish brown or purple, 0.2–0.4 mm ; ovary more or less conic, densely pubescent ; styles 3(-4), (1-)1.6-2.4 mm, basally pubescent. Seeds probably 1 per fruit, to 1.2 mm (mature seeds not seen).
Vernacular names and uses. — “Fotsivony” (Service Forestier 5627) ; “Hazomalany” (Birkinshaw et al. 333); “Hazombato” (Service Forestier 21905); “Hazombatondrano” (Service Forestier 4805); “Hazompoza” (Service Forestier 8014, 9412,16446) ;
“Hazondrano” (Service Forestier 14475) ; “Hazondroka” (Service Forestier 9743) ; “Hazontreka” (Service Forestier 6126) ; “Hazopoza” (Service Forestier 14747) ; “Iatongoro” (Réserves Naturelles 4757) ; “Ioharia” (Réserves Naturelles 7461) ; “Karaka” (Louvel 76); “Lalimboay” [Bara dialect] (Service Forestier 2238) ; “Rohandria” (Service Forestier 5327, 9743) ; Samanta (Service Forestier 14429) ; “Sana” (Decary 5044) ; “Tadolo [?]” (Decary 5127) ; “Tafaran” (Cloise l230) ; “Tanteliravina” (Service Forestier 12284, 14461) ; “Tateliravina” (Service Forestier 14414) ; “Tsitakonala” [Betsimisaraka dialect] (Service Forestier 10566, 17711 18159) ; “Tsitakonala à p.f. [petits feuilles]” (Service Forestier 10821) ; “Tsitakonalafotsy” (Service Forestier 14176) ; “Tsivalandra” (Réserves Naturelles 3814) ; “Vatongero” (Réserves Naturelles 4734).
The wood of H. oppositifolium is used for construction, for manufacture of wooden objects including fence stakes, and as firewood (Cloisel l230 ; Service Forestier 16446, 17711, 21905). Flowers are said to be sweet-scented (Nikolov 1848).
Distribution, ecology and conservation status. — Homalium oppositifolium occurs in low- to mid-elevation humid forests and in littoral or marsh forests, and very rarely extending into dry deciduous forest ; it is reported on sand, gneiss, and clay. Though sometimes described as locally rare, it is widespread ; hence the preliminary conservation status assessment is “Least Concern” [LC].
Notes. — There is only one complete herbarium specimen of the type collection of H. oppositifolium at P, which can be considered the holotype ; the second sheet comprises only fragments in two paper packets. As for H. laxiflorum, above, Sleumer (1973 : 323) stated that the type came from Foulpointe, though its label included no locality data. Du Petit-Thouars collected both on the coast near Fénérive (including Foulpointe) and around Fort-Dauphin (Dorr, 1997 : 346). Homalium oppositifolium is found at both of those locations, but since the bracts on the type specimen are not particularly large (see discussion below), it is more likely to have been collected from the region of Fénérive.
Homalium oppositifolium is distinguished by its small, opposite leaves and very pubescent flowers, with perianth indument often extending to the adaxial surfaces of sepals and petals. Several specimens from the region around Fort-Dauphin, at the southeastern extreme of the species'distribution, have enormous bracts and bracteoles, more than twice the typical length of those on more northerly specimens and unusually broad. Since some intermediate sizes are observed, and no other obvious characters were noted that consistently separate Fort-Dauphin populations from others, this is considered to be a local variant rather than a distinct taxon to be recognized under one of Scott-Elliot's previously published names. However, further study of the populations in this area would be desirable.
Homalium cymosulum was published based on Scott Elliot 3037, a reddish-flowered collection from Fort-Dauphin with a cylindrical calyx cup. The P isotype appears to be identifiable as a hybrid of H. oppositifolium × H. trigynum.
Kotozafy & Rasabo 862 (MO, P) from Ranomafana has densely pubescent glands and some resemblance to Homalium oppositifolium, but the leaves are alternate and the sepals are much shorter than the petals and very weakly pubescent. Service Forestier 17711 (P) comes from the coastal locality of Tampolo ; it has short-acuminate leaves, small long-stalked glands, and very weak gland and perianth indument. These specimens are suspected to represent hybrids, but the identity of the other parent is uncertain.
Additional material examined. — Madagascar. Prov. Antsiranana : Ambodivapaza, forêt de Farahangitra, 14°08′20″S 49°54′50″E, 315 m, 12.IV.2013, fl., Rakotonirina et al. 122 (G, K, MO) ; canton Marovato, district Ambanja [probably Tsaratanana RN], 13.XII.1952, fl., Réserves Naturelles 4734 (P) ; ibid. loc., same date, fl., Réserves Naturelles 4757 (P). Prov. Fianarantsoa : Midongy du Sud, National Park buffer zone, 23°36′41″S 47°02′05″E, 577 m, 23.VIII.2008, post-fl., Bussmann et al. 15112 (MO,P) ; Vangaindrano, edge of Midongy du Sud NP, Ambalabe Forest, 23°36’′08″S 47°02′58″E, 687-775 m, 23.VIII.2008, post-fl., Bussmann et al. 15127 (MO,P) ; Vondrozo, 17.VI.1925, fl., Decary 3852 (P) ; Midongy du Sud, 21.VIII.1926, post-fl., Decary 5044 (P) ; ibid. loc., same date, fl., Decary 5127 (MO [3 sheets], P) ; Prov. de Farafangana, 23.VIII.1926, post-fl., Decary 5151 (MO,P) ; Vallée de l'Itomampy, VI.1919, Perrier de la Bâthie 12654 (P) ; RN 25, 7 km W of Ranomafana town, 21°15′S 47°25′E, 600–900 m, 14.VI.1994, fl., Randrianasolo et al. 63(MO) ; 2 km W d'Andrambovato, bord de la rivière Tatamaly, 21°30′S 47°24′E, 1075 m, 19.X.2000, fl., Randriantafika 170(MO,P) ; Farafangana, riviere Tohakondra, 6.XI.1950, fl., Service Forestier 2238 (P) ; Fianarantsoa, Fort-Carnot, Sahavia, 30.VI.1951, post-fl., Service Forestier 4805 (P) ; Farafangana, Manombo, 11.VII.1952, fl., Service Forestier 5627 (P) ; Ambohimanga du Sud, Ambaro, 17.XI.1952, fl., Service Forestier 7049 (P) ; env. du Manombo, au S de Farafangana, 26.VI.1954, Service Forestier 9201 (P) ; Andrambovato, 30.VII.1954, post-fl., Service Forestier 12284 (P) ; Fort-Carnot, Andrambovato, parcelle B-8,10.VI.1954, fl., Service Forestier 14414 (P) ; Mananjary, Amboropotsy, 16.V.1954, fl., Service Forestier 14429 (P) ; Andrambovato, 12.VI.1954, Service Forestier 14461 (P) ; Mananjary, Ifanadiana, 1.VI.1954, fl., Service Forestier 14475 (P) ; Androrangavola, Ifanadiana, 21.IV.1954, post-fl., Service Forestier 14544 (MO,P) ; Nosy-Varika, Ampasinambo, Antanifotsy, 9.X.1954, fl., Service Forestier 14747 (P) ; Farafangana, Anjorozoro, 4.IV.1966, fl., Service Forestier 25853 (MO,P). Prov. Mahajanga : Ambodiriana, rive droite du fleuve, 700 m, 14.XII.1944, fl., Cours 1957 (MO,P) ; Ambendraria, forêt d'Ampoakafobe, à 6 km W du village d'Antsiatsiaka, 16°01′34″S 49°04′19″E, 769 m, 8.XI.2004, fl., Lehavana et al. 190 (MO,P) ; Antsakoabe, formation sur le lavaka Antakoanibata, Tsingy Beanka, 18°05′48″S 044°31′57″E, 211 m, 21.XI.2012, fl., Rakotovao et al. 6323 (MO). Prov. Toamasina : Fkt. Anjiahely, 15°24′00″S 49°26′12″E, 740 m, 14.XII.2002, post-fl., Antilahimena et al. 1476 (MO,P) ; ibid. loc., 15°23′04″S 49°26′58″E, 1005 m, 20.XII.2002, post-fl., Antilahimena et al. 1534 (MO,P) ; Soanierana Ivongo-Ampasimbola, 50 m SE of track, PDOP 2.5, 16°57′26″S 49°33′55″E, 60 m, 3.VII.1996, fl., Birkinshaw et al. 333 (MO,P) ; Antanambao, river Antsohihy, 16°47′18″S 49°41′54″E, 58 m, 30.VI.2007, fl., Birkinshaw & Andriamiarinoro 1755 (MO) ; Ambatondrazaka, bords de la Mahamaro, Anosibe,700 m,XI.1938, fl., Cours 866 (P) ; Tampina, 25.VIII, fl., Louvel 76 (P) ; Pointe à Larrée, fkt. Ambohitsara/Ampeny, forêt de Menagisy, 16°46′30″S 49°40′45″E, XI.2008, Nikolov 1848 (MO) ; Haut Anosivola, bassin du Mangoro,XI.1911, fl., postfl., Perrier de la Bâthie 6711 (P) ; [Analamazaotra] vers 1000 m alt, X. 1922, Perrier de la Bâthie 15476 (P) ; Fénérive-Est, Tampolo forestry station, along the “Grand Layon”towards the ocean, 17°17′S 49°23′E, 5 m, 31.VII.1996, fl., post-fl., Randrianasolo 451 (MO,P) ; Ambinanitelo, forêt d'Anjiabe, limite entre Befandriana Nord et Maroantsetra, suivant la piste vers Andranomena Mantsoandakana, 15°35′S 49°23′E, 17.II.2008, fl., Ravelonarivo et al. 2879 (MO) ; Moramanga, Sahanomby, 4.VII.1952, sterile, Service Forestier 6126 (P) ; Marolambo, Ambalamena, 13.XII.1953, fl., Service Forestier 8014 (P) ; ibid. loc., same date, fl., Service Forestier 9412 (P) ; Tampolo, 112 bis JB. 21, 1.VI.1954, fl., Service Forestier 10506 (P) ; Tampolo, 24.IX.1954, fl., Service Forestier 10821 (P) ; ibid. loc., 16.V.1955, post-fl., Service Forestier 14176 (P) ; district Marolambo, Morafeno, côté gauche du chemin, 29.X.1956, Service Forestier 16446 (P) ; Tampolo, 28–29.VIII.1957, fl., Service Forestier 18150 (P) ; Distr. Vavatenina, Ampasimazava, Nosibe, 3.IX.1964, fl., Service Forestier 21905 (P). Prov. Toliara : Route de Fort-Dauphin à Mahakalaky, s.d., fl., Boiteau 2141 (MO,P) ; Fort-Dauphin, s.d., fl., Cloisel 230 (P) ; ibid. loc., 15.VI.1926, fl., Decary 4027? (P) ; ibid. loc., 8.VII.1926, fl., Decary 4270 (MO, P) ; Mandena 7.5 km N of Fort-Dauphin, 24°58′S 46°59′E, 0–10 m, Gereau et al. 3295 (MO,P) ; forêt de Manantantely près Fort-Dauphin, 50–300 m, 1.III.1947, Humbert 20380 (P) ; Antsotso,TGK 42, forêt de Bemangidy, 24°35′17″S 47°08′42″E, 28 m, s.d., fl., Randriatafika 861 (MO) ; Fort-Dauphin, Ifarantsa, 24.IV.1952, fl., Réserves Naturelles 3814 (MO [2 sheets],P) ; ibid. loc., 25.V.1955, fl., Réserves Naturelles 7461 (P) ; Fort-Dauphin, May, postfl., Scott Elliot 2639 (P) ; Mandena, 11.VI.1952, fr., Service Forestier 5327 (P) ; Fort-Dauphin, Andreø, 2.IV.1954, fl., Service Forestier 9743 (P).
10. Homalium pseudoboinense Appleq., spec, nova (Fig. 2B–C, 3).
Typus : Madagascar. Prov. Toamasina : env. de la Baie d'Antongil, bassin de la Mahalevona, entre Ankovana et Ambatondradama, III. 1953, fl., Service Forestier 8866 (P [P04734315]! ; iso- : P [P04734251, P04734314, P04734316, P04734317]!).
Homalium pseudoboinense Appleq. differs from H. boinense H. Perrier in having larger flowers, stamens in groups of 3, and sepals with densest pubescence near margins.
Tree described as large ; large twigs brown ; young twigs brown, glabrous ; stipules narrowly lanceolate, 1.6–3 mm, glabrous to minutely pubescent, occasionally persistent. Leaves alternate ; petiole 6–14 mm, glabrous or glabrate ; blade broadly elliptical, 5-10.7 × 3.5-6.2 cm ; base convex to rounded (to broadly cuneate, sometimes minutely attenuate at petiole attachment) ; apex rounded to cuspidate or emarginate ; margins subentire, revolute, usually with 1 or more small glands in margins not associated with toothing ; abaxial surface glabrous, drying brown ; adaxial surface glabrous, drying darker brown. Inflorescences paniculate, with well-separated, few-flowered short side branches, at least the upper portions mostly racemiform, lateral, largely confined to twig apices, 5–15 cm, moderately to densely pubescent with very short appressed hairs ; peduncle (0.2-)1-3.5 cm, thick and somewhat angular ; pedicel 3.5–11 mm, short-pubescent ; bracts broadly ovate to suborbicular 1.3–2.3 mm, pubescent ; bracteoles lanceolate to ovate, 1.5–2.8 mm, pubescent. Flowers : sepals 5, elliptical with rounded to broadly acute apex, 5.5–6 mm, abaxial surface short appressed-pubescent, the margins usually broad, pale and more densely pubescent than central portions above the base ; calyx cup very shortly funnelform to cup-shaped, short appressedpubescent ; sepal glands irregularly trapezoid, sometimes elevated, possibly 2-lobed, 1.3-1.4 × 0.7-0.8 mm, upper surface densely pubescent ; petals obovate with rounded apex, mostly ascending, 9-10.5 × 4.2-5.4 mm, much longer than sepals, abaxial surface appressed-pubescent, densely so at base and in center, adaxial surface glabrous ; stamens in groups of 3 or 4 ; filaments 3–3.6 mm, glabrous ; anthers 0.4 mm ; ovary conic, densely villous ; styles (4-)5, 1.5–2 mm, pubescent at base. Seeds not seen.
Homalium pseudoboinense is known from only a single collection, which is over 60 years old. The locality is inland humid forest, close to the boundary between Toamasina and Antsiranana provinces, at around 500 meters in elevation.The lack of collections from a well-botanized region of Madagascar suggests that the species is likely to be very rare or a highly localized endemic. However, the type locality may be within the boundaries of the protected area of the Masoala National Park, reducing the threat of imminent extinction. In view of the lack of information available for this species, a preliminary conservation status assessment of “Data Deficient” [DD] seems most appropriate.
Notes. — Homalium pseudoboinense most closely resembles the sole western species of the section, H. boinense, but has much larger flowers with only 3 stamens per bundle and sepals more densely pubescent towards the margins ; the latter character is quite unusual. Of the other species around the Baie d'Antongil, it most closely resembles the large-leaved, sometimes large-flowered littoral species H. nobile, which has a racemose inflorescence and sepals most densely sericeous in the central portions, sometimes appearing keeled, and only slightly shorter than the petals.
Fig. 3.
- Holotype of Homalium pseudoboinense Appleq.
[Service Forestier 8866,P] [© Muséum national d'Histoire naturelle, Paris. Reproduced with permission]
![f03_34.jpg](ContentImages/Journals/cand/71/1/c2016v711a7/graphic/WebImages/f03_34.jpg)
11. Homalium pulchrum Sleumer in Bull. Jard. Bot. Natl. Belg. 43:320.1973.
Typus : Madagascar. Prov. Fianarantsoa : Farafangana, Ihorombe, Manombo, 10.I.1955, fl., Service Forestier 12931 (holo- : P [P00375173]! ; iso- : L [L0010994] image seen, P [P04734398]!).
Tree to 22 m tall ; large twigs grayish brown ; young twigs grayish or dark brown, glabrous ; stipules deltoid, ca. 0.5 mm, glabrous. Leaves partly alternate, partly opposite ; petiole 3-6(-10) mm, glabrous ; blade oblanceolate to elliptical or narrowly elliptical, 4-9(-13.7) × 1.5-3.6(-4.4) cm ; base cuneate to convex or attenuate ; apex cuspidate to rounded (or acute) ; margins subentire, seldom minutely revolute (or with few shallow rounded teeth), with 2–4 small glands per side embedded in margins toward base ; abaxial surface glabrous, drying medium to pale brown or pale greenish ; adaxial surface glabrous, drying dull greenish to grayish. Inflorescences racemose (rarely partly paniculate with a few flowers in small clusters on very short branches), the surviving flowers mostly distal, lateral, 2.3–10 cm, glabrous (sparsely minutely pubescent) ; peduncle 0.6–5 cm, slender ; pedicel 1-2(-2.5) mm, glabrous (sparsely minutely pubescent) ; bracts lanceolate to deltoid, 0.4-1.5(-2.2) mm, glabrous ; bracteoles usually absent. Flowers : sepals 4–5, creamy beige or whitish, narrowly oblong to oblong-elliptical or elliptical with irregularly rounded apex, 2.8–4 mm, abaxial surface glabrous ; calyx cup funnelform, glabrous ; sepal glands irregularly elliptical, 0.6-1 × 0.4-0.5 mm, upper surface glabrous and slightly wrinkled ; petals white, ob ovate to lanceolate with rounded apex, (3-)4-6 × 1.5-3.6 mm, usually significantly longer than sepals (rarely equal in length), abaxial surface pubescent with short appressed hairs primarily on central basal portion, with a central darker stripe, adaxial surface glabrous (sparsely pubescent at extreme base) ; filaments 0.7-1(-2) mm, glabrous ; anthers 0.3 mm ; ovary conic, densely pubescent ; styles 4(-5), 0.5–1.4 mm, basally pubescent. Seeds not seen.
Vernacular names. — “Ropasy” ( Service Forestier 13192); “Tsatoky” (Réserves Naturelles s. n.).
Distribution, ecology and conservation status. — Homalium pulchrum is native to low-elevation humid forests in southeastern Madagascar ; it is reported to occur on laterite, including laterite of basalt. It is known from only five locations, only one of which is protected ; its apparent rarity and the ongoing loss of habitat in most of its range justify a preliminary conservation status assessment of “Endangered” [EN B2ab(iii)].
Notes. — Sleumer (1973) did not note in the protologue of H. pulchrum that two sheets of the type were present at P. However, in this case he labeled only one sheet as the holotype and marked the inferior second sheet as “pars holotypi”, effectively making it an isotype.
Homalium pulchrum is part of the H. capuronii species group (see Table 1). It is among two species in that group with normally racemose inflorescences ; the other is the distinctive H. schatzii, another species of low-elevation northeastern forests, which has elliptical to obovate leaves, unusual petal indument, and huge sepal glands. It is also notable for often having narrow, oblanceolate to narrowly elliptical leaves and glabrous pedicels and rachises.
Razakamalala et al. 2583 (MO,P) is an atypical specimen with longer leaves and petioles and shorter inflorescences than any other and with petals little longer than the sepals. More typical material has been collected from the same location.
Additional material examined. — Madagascar. Prov. Fianarantsoa : Manombo RS, parcel W of Route Nationale 12,23°02′S 47°02′E, 100 m, 9–11. III.1991, fl., Schatz et al. 3192 (P) ; Manombo, 17.X.1964, fl., Service Forestier 23633 (P). Prov.Toliara : Antsotso, forêt d'Ivohibe, 24°56′22″S 47°20′27″E, 440 m, 2.XII.2005, fl., Razakamalala et al. 2583 (MO,P) ; ibid. loc., same date, buds, Razakamalala et al. 2586 (MO,P) ; Antsotso Avaratra, 24°34′03″S 47°11′57″E 403 m, 10.XII.2007, fl., Razakamalala et al. 3852 (MO,P) ; ibid. loc., 24°34′16″S 47°12′06″E, 271 m, 8.XII.2007, fl., Razakamalala et al. 3780 (MO,P [2 sheets]) ; Canton Ampasimena, Editsaky, 22.XI.1949, fl., Réserves Naturelles s.n. (P) ; Fort-Dauphin, Bemangidy, 31.III.1955, Service Forestier 13192 (P).
12. Homalium randrianasoloi Appleq., spec, nova (Fig. 2D, 4).
Typus : Madagascar. Prov. Toliara : Manantenenina, forêt de Marovony [24°06′S 47°20′E], 29.X.1990, fl., Randrianasolo et al. 191 (holo- : MO-4028861! ; iso-, P [P04734076]!).
Homalium randrianasoloi Appleq. differs from H. capuronii Sleumer in having larger leaves, some panicles with well-developed side branches, sepals and petals sometimes 5.
Tree to 10 m tall ; large twigs grayish ; young twigs brown, glabrous ; stipules linear to narrowly deltoid, < 1 mm (few seen), glabrate. Leaves alternate ; petiole 5–10 mm, glabrous ; blade elliptical to obovate or broadly (narrowly) elliptical, 6-12.5 × 2.8-6.6 cm ; base convex to rounded (cuneate in young leaves), at extreme base short-attenuate ; apex roundedacute to cuspidate, rounded, or shallowly emarginate ; margins minutely revolute with 0 to 2 basal glands just inside margin ; abaxial surface glabrous, drying greenish ; adaxial surface glabrous, drying greenish. Inflorescences paniculate, shortbranched, ridged, with most flowers borne in small clusters, sometimes with short but well-developed proximal branches, lateral mostly near twig apices, 7–10.5 cm, glabrate or glabrous proximally, the distal rachis and branches sparsely (moderately) minutely pubescent ; peduncle 1–4.8 cm, moderately sturdy ; pedicel 1.5–4.3 mm, sparsely (moderately) minutely pubescent ; bracts ovate, 0.3–2.5 mm, minutely pubescent ; bracteoles ovate, 0.5–1 mm, minutely pubescent. Flowers : sepals 4(-5), oblong with rounded apex, 2.4–4.2 mm, abaxial surface sparsely minutely pubescent ; calyx cup funnelform, moderately (sparsely) minutely pubescent ; sepal glands irregularly oblong, 0.6-1 × 0.4-0.6 mm, upper surface glabrous or sparsely short-pubescent to moderately short-pubescent in the depressed center ; petals white or pink (possibly only after anthesis), obovate to narrowly obovate with a narrow base and rounded apex, 3.7-6 × 1.6-2.6 mm, significantly longer than sepals, abaxial surface minutely pubescent especially at base and in center, adaxial surface glabrous ; filaments 1.7–2.4 mm, glabrous ; anthers 0.3 mm ; ovary flat-conic, short-pubescent ; styles 4(-5), 1.5‐2.5 mm, glabrous or sparsely pubescent especially on short fused basal portion. Seeds not seen.
Distribution, ecology and conservation status. — Homalium randrianasoloi is known from only two collection numbers made two days apart at the low-elevation humid forest of Marovony near the southeast coast north of Fort-Dauphin and southeast of Befotaka. This area has not been frequently collected, so the paucity of specimens is not clear evidence of local rarity. However, the type locality is under extreme and immediate threat : only small fragments of the Marovony forest remained at the time of the most recent vegetation mapping (Madagascar Vegetation Mapping Project, 2006), and the larger low-elevation forests to its west and southwest were at that time already completely or almost completely gone. Thus, a preliminary conservation status assessment of “Critically Endangered” [CR B1ab(iii)+2ab(iii)] seems justified. An attempt to locate another population of the species in the larger remaining forested areas of Alan'i Tsidikamboro, to the north of Amparihy Atsinanana, would be highly desirable.
Notes. — Homalium randrianasoloi is part of the H. capuronii group (see Table 1). It is most similar to H. capuronii, from which it is visually distinguished by its typically larger, broader leaves with sometimes rounded bases and sometimes betterdeveloped panicles. The leaves of the type are comparable in size to the aberrant extreme of H. capuronii's size range, while the paratype has even larger leaves, elliptical with broad bases and rounded-acute apices, but only short-branched panicles. Flowers of H. capuronii are consistently 4-merous, whereas some flowers of H. randrianasoloi are 5-merous. Known specimens of H. randrianasoloi dry greenish, which is uncommon in H. capuronii (though this character is not consistent in the latter species, and might not be in the former). In addition, H. capuronii is native to the northern province of Antsiranana and occurs only at medium to high elevations. This provides further reason to presume that these taxa are genetically distinct, though their similarity and the variability of some features within H. capuronii may make them difficult to differentiate.
The other low-elevation southeastern species in this group, H. pulchrum, has narrower leaves, oblanceolate to elliptical or narrowly elliptical with usually cuneate to convex bases and subentire margins having 2 to 4 glands per side, and its inflorescences are racemose and usually glabrous. It does not seem plausible that the observed morphology of H. randrianasoloi could have resulted from hybridization of H. pulchrum with any of the other species known from the region, which include H. brevipedunculatum, H. oppositifolium, and H. trigynum.
Paratypus.— Madagascar. Prov. Toliara : Fort-Dauphin, Marovony Forêt, 27.X.1990, post-fl.,Dumetz 1348 (MO-3853942, P [P04705534]).
Fig. 4.
- Holotype of Homalium randrianasoloi Appleq.
[Randriansolo et al. 191, MO] [© Missouri Botanical Garden, Saint Louis. Reproduced with permission]
![f04_34.jpg](ContentImages/Journals/cand/71/1/c2016v711a7/graphic/WebImages/f04_34.jpg)
13. Homalium ranomafanicum Appleq., spec, nova (Fig. 2E, 5).
Typus : Madagascar. Prov. Fianarantsoa : Ranomafana National Park, parcelle 3, S of National Road 25 at 7 km W of Ranomafana town, 21°15′30″S 47°25′00″E, 953 m, 900–1100 m, 15.XII.1994, fl., Randrianasolo & Bernardin 209 (holo- : MO-6669934! ; iso- : BR!, CAS!, G!, K!, L!, TAN, USMS).
Homalium ranomafanicum Appleq. differs from H. maringitra H. Perrier in having larger, broadly obovate (to obovate or broadly elliptical) leaves with revolute, untoothed margins bearing 0 to 2 basal glands, paniculate inflorescences.
Tree to 20 m tall, 25 cm dbh ; large twigs grayish brown ; young twigs dark brown, glabrous ; stipules broadly deltoid to ovate, 0.5–1 mm, glabrate. Leaves alternate (to subopposite) ; petiole (3-)5-8 mm, glabrous ; blade broadly obovate (to obovate, broadly elliptical), 4-7.3 × 2.1-5.1 cm ; base convex (to cuneate or rounded) ; apex rounded (to shallowly emarginate or roundedcuspidate) ; margins revolute, sometimes strongly, with 0 to 2 basal glands just inside margin ; abaxial surface glabrous, drying a warm medium brown ; adaxial surface glabrous, drying dull to pale or greenish brown. Inflorescences paniculate, often with multiple well-developed proximal branches and with many flowers borne in small clusters on short branches, lateral mostly near twig apices, (3.3-)8-16 cm, sparsely pubescent proximally, the distal branches moderately minutely pubescent ; peduncle 0.6–5.6 cm, sturdy ; pedicel 1-2(-2.5) mm, at least moderately minutely pubescent ; bracts deltoid to ovate, 0.5–1.2 mm, short-pubescent ; bracteoles broadly deltoid, 0.3–0.6 mm, short-pubescent. Flowers : sepals 4, broadly oblong to oblong with rounded apex, 1.4–2.6 mm, abaxial surface sparsely minutely pubescent ; calyx cup funnelform, moderately minutely pubescent ; sepal glands irregularly oblong to trapezoid, (0.8-)0.9-1.2(-1.5) × 0.6-0.7 mm, upper surface densely short-pubescent ; petals white, obovate with a narrow base and rounded apex, 3.6-5.2 × 1.5-2.3 mm, about twice as long as sepals, abaxial surface minutely pubescent especially at base and in center, adaxial surface glabrous ; filaments 1.7–2 mm, glabrous ; anthers 0.2–0.3 mm ; ovary nearly flat-topped at anthesis, short-pubescent ; styles 4,1.5–2.4 mm, short appressed-pubescent on fused basal portion. Seeds not seen.
Distribution, ecology and conservation status. — Homalium ranomafanicum is native to mid-elevation southeastern humid forest. The type collection, made over two decades ago, is from the national park of Ranomafana. No further collections have been seen, though thousands of specimens have been collected from Ranomafana. It is thus likely that this represents a very rare species. However, given the lack of knowledge regarding this species and the fact that its known habitat is relatively well protected, a preliminary conservation status assessment of “Data Deficient” [DD] seems most conservative.
Notes. - The type collection of H. ranomafanicum is the only known collection of its kind from the very well-collected site of Ranomafana National Park. It is notable for having broadly obovate leaves, long panicles with well-developed branches, and small 4-merous flowers with short pedicels, very short sparsely pubescent sepals, and densely pubescent sepal glands. Homalium ranomafanicum is likely to be closely related to H. maringitra and the newly described H. dorrii, which share small flowers with mostly sparsely pubescent sepals and densely pubescent sepal glands. It seems most similar to H. maringitra, which is known from mid-elevation humid forests much farther north, and which similarly has petals almost twice as long as the sepals. The leaves of H. maringitra are usually smaller, or at least narrower, and mostly elliptical rather than obovate ; its leaf margins are toothed or wavy with multiple glands, its inflorescences racemose or racemiform, and its pedicels and sepals frequently longer than those of H. ranomafanicum. Homalium dorrii has narrower leaves and longer sepals, so that the petals only modestly exceed the sepals (see Fig. 2A and 2E for a comparison). The only species of sect. Eumyriantheia previously known from southeastern midelevation humid forest is H. oppositifolium, which differs from H. ranomafanicum in numerous characters (e.g., its leaves are mostly elliptical, inflorescences racemose, sepals 5–6 in number and longer both absolutely and relative to the petals, and abaxial surfaces of the sepals and petals densely pubescent).
14. Homalium schatzii Appleq., spec, nova (Fig. 2F–G, 6).
Typus : Madagascar. Prov. Toamasina: 1–2 km E of Fampanambo, 15°22′35″S 49°37′46″E,20 m, 28.I.1999, fl., Schatz et al. 3850 (holo- : P [P04705556]! ; iso- : G!, K!, MO!, TEF).
Homalium schatzii Appleq. differs from H. randrianasoloi Appleq. in its racemose inflorescence, larger sepal glands, and abaxial surface of petals densely appressed-pubescent with a pronounced narrow glabrate stripe.
Description. - Tree to 16 m tall ; large twigs pale brown ; young twigs pale brown, glabrous ; stipules deltoid, 0.5 mm, glabrous. Leaves alternate ; petiole 5–8 mm, glabrous ; blade elliptical to obovate, 6-11.5 × 2.8-6.2 cm ; base convex ; apex rounded to rounded-cuspidate, rounded-obtuse or emarginate ; margins subentire with 1–2 small basal glands per side ; abaxial surface glabrous, drying brown ; adaxial surface glabrous, drying dark brown. Inflorescences racemose with flowers borne in groups of 1 to 3 at the termination of a prominent ridge, lateral, 5–8.3 cm, glabrous proximally to minutely pubescent distally ; peduncle 3.5– 4.3 cm, noticeably flattened ; pedicel 3–5 mm, minutely pubescent ; bracts deltoid, 0.3–1.5 mm, glabrous ; bracteoles usually absent. Flowers : sepals 4, narrowly oblong to oblong-ovate with rounded (to rounded-acute) apex, 3.4–4.6 mm, abaxial surface glabrate to sparsely and minutely pubescent ; calyx cup funnelform, glabrate to sparsely and minutely pubescent ; sepal glands roughly trapezoid to elliptical or nearly square, 0.9-1.6 × 0.7-1 mm, upper surface glabrous ; petals obovate with rounded apex, 4.7-6.5 × 2.4-2.8 mm, much longer than sepals, abaxial surface moderately to densely short appressed-pubescent with a conspicuous glabrate stripe down center, adaxial surface glabrous ; filaments 2.4–3.2 mm, glabrous ; anthers 0.4 mm ; ovary conic, short-pubescent ; styles 4-5,2–2.5 mm, short appressed-pubescent especially at base. Seeds not seen.
Distribution, ecology and conservation status. — Homalium schatzii is native to low-elevation humid forest on laterite in northeastern Madagascar ; it is known from only the type collection, from a locality that is subject to ongoing degradation. As for H. pseudoboinense, from a quite different habitat but also near the Baie d'Antongil, the dearth of specimens despite a relatively large number of collections made in that region of Madagascar allows the presumption that the species is very rare or a highly localized endemic. Thus a preliminary conservation status assessment of “Critically Endangered” [CR B2ab(iii)] seems appropriate.
Notes. — Homalium schatzii is part of the H. capuronii group (see Table 1), and is the only species of that group that occurs near Masoala in the northeast. It is distinguished within that group of species by the combination of racemose inflorescences, very large sepal glands, and an unusual pattern of corolla indument, glabrate in a stripe down the center but often relatively dense to near the apical margins, where most species have sparser indument.Two other large-leaved species, H. nobile and H. pseudoboinense, occur in the same region. Both have larger, 5-merous flowers that have dense sepal indument and lack the unusual corolla indument seen in H. schatzii.
Fig. 5.
- Holotype of Homalium ranomafanicum Appleq.
[Randrianasolo & Bernordin 209, MO] [© Missouri Botanical Garden, Saint Louis. Reproduced with permission]
![f05_34.jpg](ContentImages/Journals/cand/71/1/c2016v711a7/graphic/WebImages/f05_34.jpg)
Fig. 6.
- Holotype of Homalium schatzii Appleq.
[Schatz et al. 3850, P] [©Muséum national d'Histoire naturelle, Paris. Reproduced with permission]
![f06_34.jpg](ContentImages/Journals/cand/71/1/c2016v711a7/graphic/WebImages/f06_34.jpg)
15. Homalium trigynum (Baker) Sleumer in Bull. Jard. Bot. Natl. Belg. 43 : 316. 1973.
≡ Weinmannia trigyna Baker in J. Bot. 20 : 109. 1882.
Typus : Madagascar. Prov. Fianarantsoa: Tanala country [E de .], Baron 292 (holo- : K [K000231476] image seen ; iso- : L [L0011032] image seen).
≡ Homalium urceolatum Scott-Elliot in J. Linn. Soc., Bot. 29 : 22. 1891. Typus : Madagascar. Prov. Toliara : Fort-Dauphin, V.18??, fl., Scott Elliot 2662 (holo- : K [K000231477] image seen ; iso- : P [P04679671]!).
Tree to 15 m tall, 50 cm dbh, with brownish to whitish bark ; large twigs brown ; young twigs brown to pale brown, shortpubescent (glabrous) ; stipules deltoid, 0.5–0.8 mm, short-pubescent or glabrous. Leaves alternate to opposite, arrangement often variable ; petiole 4-10(-16) mm, short-pubescent (glabrous) ; blade narrowly elliptical to elliptical (to oblanceolate or obovate), 4.2-8.5(-10.7) × 1.5-4(-4.5) cm ; base convex (to cuneate) ; apex rounded to obtuse, acute, or cuspidate (emarginate) ; margins shallowly serrulate (crenate-serrulate) with several glands inside tooth apices or entire to subentire (sometimes revolute) with 0 to 2 glands near base ; abaxial surface pubescent on midrib (glabrous), drying brown ; adaxial surface glabrous (sparsely pubescent on midrib), drying brown, darker than abaxial surface or grayish. Inflorescences racemose or spicate with flowers borne singly, lateral, (2-)3-14 cm, short-pubescent (to glabrous on peduncle) ; peduncle (0.3-)0.5-2.5 cm, slender ; pedicel 0.5-1(-3) mm or absent, short-pubescent ; bracts broadly deltoid to ovate, (0.3-)0.6-1.5 mm, short-pubescent ; bracteoles broadly deltoid to ovate, (0.3-)0.5-1.2 mm, short-pubescent. Flowers : sepals 4–5, white to cream (sometimes becoming pink), ovate with acute apex, 1.3-2.4(-3.5) mm, abaxial surface moderately to densely (sparsely) appressed-pubescent ; calyx cup cup-shaped, usually elongated, or cylindrical with a broad rounded base, appressed-pubescent ; sepal glands irregularly elliptical to suborbicular, often little elevated, 0.7-1 × 0.4-0.7 mm, upper surface short-pubescent ; petals white to cream (sometimes becoming pink), oblanceolate to spatulate with acute apex, 1.7-2.9(-3.4) × 0.6-1(-1.3) mm, modestly shorter or longer than sepals, abaxial surface appressedpubescent, adaxial surface glabrous ; filaments (1.3-)1.7-2.5 mm, glabrous ; anthers 0.2–0.3 mm ; ovary flat-conic, pubescent ; styles 3–4,1.3–1.8 mm, pubescent at base (or for most of length). Seeds 1–2, ovoid to subglobose, ca. 2 mm.
Vernacular names and uses. — “Andrafeko” (Service Forestier 1142) ; “Fandramanara [?]” (Service Forestier 3245) ; “Hazondrano” (Service Forestier 21663) ; Marandravy (Rabevohitra et al. 3713) ; Troihy (Cours 5286) ; “Tsimioroka” [Tsimihety dialect] (Service Forestier 19050) ; “Varona” (Service Forestier 2303).
The wood of H. trigynum is reported to be used in the manufacture of items including canoes (Service Forestier 19050). A strong infusion of the bark is used to treat hemorrhage (Cours 5286).
Distribution, ecology and conservation status. — Homalium trigynum is widespread, justifying a conservation status of “Least Concern” [LC], though it might be noted that it is not particularly common, that most known habitat is unprotected, and that distinctive morphological variants, found in a smaller number of localities, might be considered vulnerable if they were formally recognized. Those variants may have different ecological preferences.The southern or eastern form described below usually occurs in low-elevation to sublittoral humid forests, while the northern form is found in mid- and low-elevation forests, with intermediates appearing at high altitudes in the southeast. The species has been reported on gneiss and clay.
Notes. — Homalium trigynum is widespread and very distinctive ; it is the only species in sect. Eumyriantheia with small flowers having both sepals and petals with acute apices, a broad, round-based calyx cup, very short or sometimes absent pedicels, and sometimes sparse pubescence inside the upper part of the ovary, to which the seeds are confined. Though it is an outlier within this section, placement within sect. Polyanthera would be even more problematic (Applequist, unpubl. data).The slender racemose inflorescences with shortpedicellate to sessile flowers borne singly have a characteristic appearance that allows easy identification.
Geographically correlated morphological variation exists. Almost all specimens from eastern and southeastern forests have petals longer than the sepals and usually toothed leaf margins with several glands, while northern specimens (from the province of Antsiranana and rarely into Mahajanga, usually in high-elevation forests) have petals shorter than the sepals and usually subentire leaf margins with 2 (less often 0 or 1) glands. However, a few intermediate specimens exist, including two specimens with toothless leaf margins from very high altitudes at the southeastern locality of Ambatofinandrahana. Further, one specimen entirely consistent with northern morphology appears to be from the southeast (the locality is given as Mania, a river in Fianarantsoa). It is suspected that ecological preferences play a strong role in creating separation between these forms. Since their geographic distributions are not entirely consistent, it seems most conservative not to formally recognize them at this time.
Réserves Naturelles 8422 (P) from Sambava has flowers that resemble those of Homalium trigynum, with a broad-based calyx cup, but at least some inflorescences are long panicles, with flowers in clusters and sometimes borne on long side branches well above the base. This specimen is suggested to be a hybrid involving H. trigynum and an unidentified second species (possibly H. capuronii).
Homalium cymosulum, known only from the type, is noted above under H. oppositifolium to represent a probable hybrid of H. oppositifolium × H. trigynum.
Additional material examined. — Madagascar. Prov. Antsiranana : Anjahana, 13°21′15″S 49°11′01″E, 118 m, 7.VI.2005, fr.,Hong-Wa et al. 313 (MO, P) ; Région du Sambirano, Mananjeba, 300 m, VIII.1913, fr., Perrier de la Bâthie 6701 (P) ; Bassin supérieur de la Loky,XI.1909, fr., Perrier de la Bâthie 6713 (P) ; forêt de Maromaniry, à 5 km au N d'Ampisarahina, 13°38′41″S 49°32′27″E, 1199 m, 10.XI.2007, buds, Randriambololomamonjy et al. 357 (P) ; N à 6 km d'Antsarabasia, 13°35′39″S 49°59′10″E, 13.XI.2001, fl., Randrianaivo 755 (MO) ; Sambava, Ambendrana, bord rivière, 2.XII.1948, fl., Service Forestier 1142 (P [2 sheets]) ; Diego-Suarez, Sahafary, 6.VII.1956, fl., Service Forestier 15978 (P) ; ibid. loc., same date, fr., Service Forestier 15980 (P) ; Sambava, village le plus proche Analampotsy, Andaimpotsy, 800 m, 23.VIII.1956, fl., Service Forestier 19050 (P) ; Sambirano, bord de cours d'eau à la base SW de l'Ambohipiraka (Ambilobe), 9.III.1964, fl., Service Forestier 23408 (MO,P [2 sheets]). Prov. Fianarantsoa : Dist. Farafangana, Vondrozo, 2.IX.1926, fr., Decary 4874 (P) ; ibid. loc., 28.VIII.1926, fr., Decary 5075 (P) ; env. d'Ambatofinandrahana, 1600–1800 m, 16.II.1938, fl.,Decary 12946 (P) ; Mananjary zone côtière, III-IV.1909, fl., Geay 8019 (P) ; ibid. loc., same date, fl., Geay 8020 (P) ; ibid. loc., same date, fr., Geay 8021 (P) ; ibid. loc., same date, fl., Geay 8022 (P) ; Mania, bords du torrents, 700 m, 19.III, Perrier de la Bâthie 12547 (P) ; Fkt. et village Antaviavola, bord de la rivière Matanga, 23°30′47″S 47°32′32″E, 40 m, fl., Raharimampionona et al. 180 (MO,P) ; District Ivohibe, canton Ivongo, 22.X.1959, fl., Réserves Naturelles 10350 (P) ; District de Mananjary, Pohimasy 17.IV.1954,fl., Service Forestier lOll9 (P) ; Fort-Carnot, village le plus proche Ambohimahavelo,Tantahaly, 17.II.1964, fl., Service Forestier 21663 (P) ; Berges de la Namorona, près de Mangalaniheletra, entre Ifanadiana et Tolongoina, 29.I.1964, fl., Service Forestier 23219 (P [2 sheets]) ; Berges de la Kelibezizitra, près d'Ankafotra, sur le plateau d'Itremo (entre Itremo et Amborompotsy), Ambatofinandrahana, vers 1450 m, 20.II.1970, fl., Service Forestier 29055 (MO,P [2 sheets]). Prov. Mahajanga : Befandriana Nord [station], Antsirebika, Ampombilava, 25.VIII.1942, fl., Cours 5286 (P). Prov. Toamasina: Soanierana Ivongo, 27.XII.1949, fl., Service Forestier 2303 (P) ; Vatomandry, Analatsara, 17.III.1951, fl., Service Forestier 3245 (P). Prov. Toliara : Fort-Dauphin, suivant torrent barrage JIRAMA, 24°58′05″S 46°58′03″E, 1.X.2000, post-fl., Rabevohitra et al. 3713 (G, K, MO) ; Fkt. Analambendrana, forêt de Lakandava, 24°58′14″S 46°57′49″E, 180 m, 23.XI.2002, fl., Randrianaivo et al. 833 (MO, P).
Acknowledgements
I thank the Muséum national d'Histoire naturelle for permitting study of collections at P ; Sovanmoly Hul, Peter Phillipson, Simon Verlynde, and Jacques Florence for assistance during my visit and useful discussions ; George Schatz and Sue Zmarzty for helpful comments on a draft version of the manuscript ; Robbie Hart for assistance with image file formatting ; Martin Callmander for editing, and Matthieu Berthod for assembling Fig. 2.