Typus: Lijndenia laurina Zoll. & Moritzi

Shrubs or small to medium-sized trees, evergreen, glabrous ; wood extremely hard ; young branchlets terete to distinctly quadrangular (quadrangular-alate in L. melastomoides). Leaves opposite, petiolate, lacking stipules, subcoriaceous to thickly coriaceous and mostly appearing granular or papillose-muricate on drying (owing to the presence of ramiform sclereid idioblasts in the mesophyll) ; leaf-blades ± distinctly 3-nerved (= nervation strongly acrodromous), or in some of the Madagascan spp. apparently uninervate with lateral nerves intramarginal and weaker than the midnerve (= obscurely acrodromous), elliptic (to obovate or oblanceolate in some Madagascan spp.), ± distinctly acuminate at apex. Cymes borne in the leaf-axils or in fascicles at the leafless nodes of older branchlets (lower down on the trunk in L. ramiflora), ± distinctly pedunculate (the peduncles very short to ± absent in L. laurina, L. danguyana and L. memecyloides), umbelliform to capitellate (or 2–3 × branched with secondary inflorescenceaxes up to 9 mm in L. barteri and L. brenanii) ; bracts ± persistent and with a pair of bracteoles partially fused to form a cupule (false calyx) immediately subtending each individual flower. Flowers small, uniformly 4-merous, sessile or borne on long slender pedicels (the latter only in the case of the Madagascan spp.), mostly bisexual (androdioecious in L. laurina) ; calyx margin ± distinctly 4-lobed (not truncate) ; petals mostly white (blue in most of the Madagascan spp.), spatulate to obovate or suborbicular, unguiculate at base, ± auriculate above the claw in the Madagascan spp. ; anthers dolabriform, on long slender filaments ; oil-gland on dorsal side of anther connective uniformly present in the Madagascan spp., variably present to reduced or absent in the remaining spp. ; style slender, exserted from the corolla in bud (the flowers thus being protogynous) ; top of ovary lacking interstaminal partitions, the epigynous chamber thus appearing smooth ; ovary unilocular, ovules 2–12. Fruits berry-like, ± globose, crowned by the persistent calyx ; seeds generally solitary (occasionally 2) ; embryo with a short hypocotyl and leafy cotyledons, the inner cotyledon bent and rolled around the involute edge of the outer cotyledon.

Typus: Madagascar. Prov. Fianarantsoa: Farafangana, Ihorombe, Morarano (Tokohandra), 23.X.1952, fl., Service Forestier 6391 (holo- : P [P00257942]! ; iso- : P [P00257943]!, TEF!).

Affinis L. memecyloidi R.D. Stone sed laminis foliorum anguste ellipticis (non oblanceolatis vel obovatis) ad apices distincte angusteque acuminatis (non rotundatis vel retusis vel sub-acuminatis), pedunculis cymarum 7–15 mm (non 1–3 mm) longis, floribus in quoque cyma numero 7–16 (non 3–5) differt.

Habit not specified, presumably a shrub or small understory tree ; young branchlets terete ; internodes mostly 1.7–3 cm. Leaves apparently 1-nerved (only the midnerve clearly evident, the lateral nerves intramarginal and ± obscure), subcoriaceous, finely granular in dried material, on petioles mostly 3–4 mm; blades narrowly elliptic, (5.3-)5.8-6.5 × 1.9-2.4 cm, the apex distinctly and narrowly acuminate (the acumen 5–12 mm) ; transverse veins invisible. Cymes umbelliform and 7-16-flowered, solitary or in fascicles of 2–3 mostly at the leafless nodes of older branchlets, sometimes also solitary or geminate in the leaf axils ; peduncles 7-12(-15) mm, compressed, the apex with a pair of persistent, triangular, keeled bracts c. 2 mm, some cymes with an additional axis extending 2–4 mm above the first group of flowers ; each flower subtended by a pair of persistent, concrescent bracteoles forming a cupule or involucre from which emerges the pedicel 1–3 mm. Hypantho-calyx cupulo-patellate, 1.5 × 2 mm, the margin shallowly 4-sinuate or with calyx lobes slightly triangular ; petals 1.5 × 1.5 mm, unguiculate, limb ± sagittate with apex acute, margins convex and base abruptly truncate to shallowly cordate-auriculate above the claw 0.5 mm ; staminal filaments c. 3 mm, anthers dolabriform, 1 × 0.5 mm, the anther sacs positioned fronto-ventrally, connective dorsally incurved by an elliptic oil-gland positioned towards the anterior end, prolonged at the posterior end into an acute beak ; style filiform, 8 mm. Fruits not seen.

Etymology. — The epithet acuminata is an adjective referring to the distinctly acuminate leaf apices of this species, this being the main diagnostic feature separating it from the closely related L. memecyloides and L. densiflora.

Distribution and ecology. — Known only from the type collection made in Fianarantsoa Province, along the southeastern coast of Madagascar about 30 km south of the city of Farafangana (Fig. 2). The label of the isotype sheet in TEF indicates the habitat as forest on coastal dunes.

Conservation status. — Lijndenia acuminata is known from a single location with an area of occupancy (AOO) of 4 km² (assuming a 4 km² grid cell size). The type locality is very near or adjacent to parcelle 2 of the Réserve spéciale de Manombo, but it appears the reserve boundary has been drawn in a way that excludes the area of dunes behind the immediate coast. Given the severe loss of forested habitats in the Farafangana region and the fact that L. acuminata has not been seen in more than 50 years, it is quite possible that the species is already extinct, although more exhaustive surveys would be needed to establish this beyond a reasonable doubt. Lijndenia acuminata is thus provisionally assessed as “Critically Endangered” [CR B2ab(iii)] according to the IUCN Red List Categories and Criteria (IUCN, 2012).

Notes. — Lijndenia acuminata is closely related to (and previously confused with) L. memecyloides, but distinguished by the combination of leaf blades narrowly elliptic with apex distinctly and narrowly acuminate (versus blades narrowly elliptic to oblanceolate or obovate with apex rounded or retuse to vaguely obtuse-acuminate), cymes borne on peduncles 7-12(-15) mm (versus mostly 1–3 mm), and flowers numbering 7–16 per cyme (versus cymes mostly 3-5-flowered). The type locality of L. acuminata is also isolated by a distance of c. 625 km from the nearest known locality of L. memecyloides (i.e. near the town of Foulpointe [Mahavelona] in Toamasina province).

= Memecylon danguyanum H. Perrier in Mém. Acad. Malgache 12 : 210. 1932.

= Spathandra danguyana (H. Perrier) Jacq.-Fél. in Adansonia ser. 2, 18 : 228. 1978.

Lectotypus (designated here) : Madagascar. Prov. Toamasina : Analamazaotra, XI.1925, fl., Louvel 5 (P [P00057564]!). Syntypus: Madagascar. Prov. Toamasina : Analamazaotra, II. 1919, fr., Thouvenot 123 (P [P00057565, P00257949, P00257950, P05207163, P05207164, P05207165]!, K [K000276111, K000313593]!).

Tree 7 to 20 m; young branchlets terete, blackish; older branchlets whitish and often with fine horizontal fissures (lenticels?). Leaves evidently 3-nerved (the midnerve prominent on the lower surface; principal pair of lateral nerves only slightly visible on the lower surface, situated c. 5 mm from the margins at the midpoint of the blade, evanescent toward the apex; an additional, very weak pair of lateral nerves at the revolute margins), coriaceous, granular in dried material, discolored; petiole 5–8 mm; blades mostly obovate to oblanceolate (varying to ± elliptic), 5-9.5(-13) × 2.5-4.5 (-6) cm, attenuate and decurrent on the petiole, rounded to retuse at the apex. Cymes subsessile (peduncle ± absent or to c. 1 mm), umbelliform, fascicled at the leafless nodes of older branchlets ; each flower subtended by a pair of fleshy bracteoles fused at the base to form a cupule ; pedicel 6–10 mm. Hypanthocalyx campanulate to cupulo-patellate, 2 × 3 mm, the margin sinuate and minutely 4-toothed; petals blue to pale bluish-purple, orbicular, limb 2 – 3 mm in diameter, apex rounded to apiculate, base abruptly narrowed and ± auriculate above the claw 0.7 mm; staminal filaments 4.5–6 mm, anthers 2 mm, anther sacs fronto-ventral, connective incurved by the median gland, extremity conical; style slender, 10–12 mm; ovary 10–12-ovuled. Fruit globose, 8 mm in diameter, asymmetrical; calycinal crown not prominent.

Distribution and ecology. — An endemic of montane forest at elevations of about 1000 m along the eastern escarpment bordering Madagascar’s central plateau (Fig. 3), in Toamasina province (Moramanga region and to the north near lac Alaotra) and Fianarantsoa province (Ranomafana National Park).

Conservation status. — Lijndenia danguyana is known from six locations and has an extent of occurrence (EOO) of 2,390 km². Along Madagascar's eastern escarpment there is presently very little forest remaining, and this extraordinary loss of habitat must have produced substantial population declines in many formerly common and widespread forest species, including L. danguyana which is an understory tree with very hard wood, a slow growth rate and a projected long generation time. Lijndenia danguyana is thus provisionally assessed as “Vulnerable” [VU B1ab(iii)] according to the IUCN Red List Categories and Criteria (IUCN, 2012). It should be noted, however, that some occurrences of this species would seem to lie within protected areas, e.g. the Réserve spéciale ď Analamazaotra and the national parks of Andasibe-Mantadia and Ranomafana.

Notes. — In the protologue of Memecylon danguyanum (Perrier de la Bâthie, 1932) there were two collections cited, one with flowers (Louvel 5) and the other with fruits (Thouvenot 123). The flowering collection has been designated here as the lectotype.

This species was previously illustrated by Perrier de la Bâthie (1951 : fig. 45 : 9–16, as Memecylon danguyanum) and by Jacques-Félix (1978b : tab. 2b, as Spathandra danguyana; 1985b : tab. 28 : fig. 6–11).

Jacques-Félix (1985b) described the petals of L. danguyana as abruptly narrowed but not auriculate above the claw. A reexamination of the available flowering material indicates that the petals of the lectotype (Louvel 5, P) are indeed lacking auricles, but these are present in Service Forestier 28436 (P) and Randrianasolo & Rasabotsy 29 (CAS).

Additional material examined. — Madagascar. Prov. Fianarantsoa : Ranomafana NP, parcelle 3, S of National Road 25 at 7 km W of Ranomafana, 21°15′30″S 47°25′00″E, 30.XI.1993, fl., Randrianasolo & Rasabotsy 29 (BR, CAS, G, K, MO, P,TAN, WAG). Prov. Toamasina : Périnet, 28.VIII.1952, ster., Service Forestier 153-B-R-172 (TEF); Befody, lac Alaotra, 27. VII. 1952, ster., Service Forestier 503-R-56 (MO, P, TEF); Distr. Moramanga, C^ton Périnet, Antsampandrano, 17.X.1962, ster., Service Forestier 21539 (P); ibid. loc., 25.X. 1962, ster., Service Forestier 21539-bis (P [2 sheets]); Ankazomanitra, village le Toby, km 45 route Moramanga-Anosibe, 8.XI.1968, fl., Service Forestier 26815 (P, TEF); W d' Antanandava, km 45 route Moramanga-Anosibe, XI.1968,fl., Service Forestier 28436 (K, MO, P [2 sheets], S, TEF, WAG); Moramanga, Andasibe, Réserve faune d'Analamazaotra, 16.I.1984, fr., Service Forestier 32548 (TEF); Andasibe-Mantadia PN, 14 km en voiture au NE de la mine de graphite, 18″53′00″S 48″27′30″E, 13.XI.2001, ster., Stone et al. 2377 (CAS, P, TAN).

Typus: Madagascar. Prov. Antsiranana: Daraina region, forêt de Binara, 13°16′19″S, 49°35′59″E, 29.XI.2006, fl., Gautier & Chatelain 4951 (holo-: G [G00340058]!; iso-: CAS-1104864!, MO, P,TEF, Herb. Darainense).

Affinis L. danguyanae (H. Perrier) Jacq.-Fél. sed laminis foliorum parvioribus (3-5 × 1.5–3 cm non 5-13 × 2.5–6 cm) ut videtur uninervis (non conspicue trinervis), nervis lateralibus invalidis intramarginalibus differt.

Tree 20 m, the trunk with diameter 40 cm at breast height ; branchlets with whitish gray bark, the youngest compressed and longitudinally grooved on the two faces, with age becoming terete, stout and thickened at the defoliated nodes ; internodes (0.5-)1-2.5(-4) cm. Leaves apparently 1-nerved (midnerve clearly visible, finely impressed on the upper surface, somewhat prominent on the lower ; lateral nerves percurrent but only faintly visible, situated 1–2 mm from the revolute margins), subcoriaceous, finely granular in dried material ; petioles 2.5–5 mm ; blades elliptic to obovate, 3-5 × 1.5-3 cm, cuneate at the base, attenuate and decurrent on the petiole, rounded and ± retuse at the apex ; transverse veins scarcely visible, 4–5 pairs spaced 4–6 mm apart, somewhat oblique relative to the midnerve. Cymes umbelliform and 3-7-flowered, in fascicles of 1–4 at the leafless nodes of older branchlets, subsessile or with peduncle c. 1 mm; bracts not evident ; individual flowers subtended by a pair of persistent, truncate-suborbicular bracteoles c. 0.25 mm forming a cupule or involucre from which emerges the pedicel 4–7.5 mm. Hypantho-calyx cupulo-patellate, 3 × 3 mm, the margin shallowly sinuate to truncate and remotely 4-denticulate ; corolla rounded in bud, white, the style long-exserted, pale violet ; petals at anthesis pale violet with white margins, 2 × 2.5 mm, unguiculate-hastate with a pair of rounded to pointed lobes 0.3 mm situated about halfway between the base and the apex, the apex broadly rounded and shallowly cucullate, with a pair of auricles 0.6–0.75 mm at the base of the limb, the claw 0.5 × 0.25 mm; staminal filaments 3–6 mm (the epipetalous filaments noticeably longer than the episepalous ones), pale violet ; anthers 1.75 mm, thecae fronto-ventral, yellow ; connective white, incurved by the median dorsal oilgland 0.3 mm, extremity conical-acute ; style slender, 10 mm, pale violet. Fruits not seen.

Etymology. — The species epithet refers to the Daraina region of northeastern Madagascar, which in the last two decades has been the subject of much biological research and conservation interest (including extensive plant collecting by Dr. L. Gautier and colleagues of the Conservatoire et Jardin botaniques de la Ville de Genève).

Distribution and ecology. — The type and only known locality of L. darainensis is in the Binara forest (Daraina region, Antsiranana Province) at elevation 920 m (Fig. 3).This species and L. danguyana are the only two Madagascan Lijndenias inhabiting montane forest, all other species being found at low elevations along or near the eastern coast.

Conservation status. — Lijndenia darainensis is known from a single location and has an AOO of 4 km².The Binara forest, in spite of its protected-area status within the Station forestière à Usage multiple de Loky-Manambato (gazetted in 2005), is subject to anthropogenic pressures including removal of hardwood timber, slash-and burn-agriculture, and pasturage of zébu cattle (Rakotondravony, 2006). Lijndenia darainensis is thus provisionally assessed as “Vulnerable” [VU D2] according to the IUCN Red List Categories and Criteria (IUCN, 2012).

Notes. — Lijndenia darainensis has been previously confused with L. danguyana. The leaves of the two species are similar, but in L. darainensis the lateral nerves are very weak and situated 1–2 mm from the margins whilst in L. danguyana they are more clearly visible and situated c. 5 mm from the margins at the midpoint of the blade. The type locality of L. darainensis is also isolated by a distance of c. 450 km from the nearest known locality of L. danguyana (i.e. near lac Alaotra in Toamasina province).

The blue flowers and apparently 1-nerved, cuneate-obovate leaves of L. darainensis also resemble those of L. roborea. These two species differ in stature (L. darainensis a tree 20 m versus a shrub or tree 2–6 m in L. roborea) as well as the texture of the leaves (thinly coriaceous with intramarginal nerves faintly visible versus thickly coriaceous with intramarginal nerves ± invisible). Moreover, L. darainensis inhabits montane forest in extreme northeastern Madagascar whilst L. roborea is found in littoral forest along the island's east-central coast.

Typus : Madagascar. Prov. Antsiranana: env. de Lohanantsahabe (haute Antsahabe, affluent rive gauche de la Lokoho), entre Sambava et Andapa, 9.XII.1966, fl., Service Forestier 27162 (holo-: P [P00257945]!; iso-: G [G00341693]!, K!, MO-4373720!, S!,TEF!, WAG!).

Affinis L. memecyloidi R.D. Stone sed laminis foliorum ellipticis (non anguste ellipticis vel oblanceolatis) ad apices late obtuseque breviacuminatis (non rotundatis vel retusis vel subacuminatis), cymis in quoque fasciculo numero 1–6 (non 1–2), floribus in quoque cyma numero 5–14 (non 3–5) differt.

Tree to 8–10 m; branchlets terete ; internodes (0.8-)1.52.5(-3.1) cm. Leaves apparently 1-nerved (only the midnerve clearly visible, the lateral nerves intramarginal and ± obscure), subcoriaceous, finely granular in dried material, on petioles 3–6 mm; blades elliptic, 3.3-5.3(-7.7) × 1.5-2.5(-3.2) cm, the apex shortly and obtusely acuminate (the acumen mostly 3–6 mm); transverse veins not evident or ± faintly visible in dried material, oriented at an oblique angle relative to the midnerve. Cymes umbelliform and mostly 5-9(-14)-flowered, solitary or in fascicles of 2-6 at the leafless nodes of older branchlets, sometimes also in groups of 1–4 in the axils of uppermost nodes; peduncles mostly 3-5(-8) mm; each flower subtended by a pair of persistent, concrescent bracteoles forming a cupule or involucre from which emerges the pedicel 1–2 mm. Hypantho-calyx cupulo-patellate, 1.25 × 2 mm, the margin shallowly 4-sinuate or with calyx lobes slightly triangular; petals white, reflexed at anthesis, 1.25 × 1 mm, unguiculate, limb orbicular with base abruptly truncate to shallowly cordate-auriculate above the claw 0.25 mm; stamens borne on bluish filaments 1–2.5 mm, anthers dolabriform, 1 × 0.5 mm, the anther sacs positioned at the anterior end, connective dorsally incurved by the medially positioned oil-gland, the posterior end prolonged, extremity obtuse to subacute; style bluish, filiform, 4 mm. Fruits not seen.

Etymology. — The species epithet densiflora refers to the densely flowered aspect which is perhaps the main characteristic setting this species apart from its closely related congeners L. memecyloides and L. acuminata. It is caused by the relatively large number of cymes per fascicle, the relatively large number of flowers per cyme (especially in comparison to L. memecyloides), and the relatively short pedicels subtending individual flowers, the result being that the individual cymes appear congested with flowers.

Distribution and ecology. — An endemic of northeastern Madagascar (Antsiranana province) in the region to the northwest and southwest of the city of Sambava, the two known localities being approximately 15 to 25 km inland from the coast and about 40 km apart from each other (Fig. 2). Habitat not specified but presumably in lowland humid forest. Elevation estimated as 80 to 150 m above sea level. A concerted effort should be made to relocate L. densiflora, particularly in the protected area Makirovana-Tsihomanaomby (gazetted in 2015) which consists of 53 km² of low-elevation forest remnants situated to the north of the river Bemarivo and west of the Route nationale no. 5a (between the towns of Sambava and Antsirabe Avaratra).

Conservation status. — Lijndenia densiflora is a poorly known species that has not been collected again within the past 50 years. There are just two known locations and an AOO of 8 km².The possibility exists that the species is already extinct, but there have been some recent examples of other so-called “forest phantoms” having been rediscovered after not being seen for many years (Schatz et al., 1998 ; Stone, 2012). At present, L. densiflora is provisionally assessed as “Critically Endangered” [CR B2ab(iii)] according to the IUCN Red List Categories and Criteria (IUCN, 2012).

Notes. — Lijndenia densiflora is closely related to (and previously confused with) L. memecyloides, but distinguished by the combination of leaf blades elliptic with apex shortly and obtusely acuminate (versus blades narrowly elliptic to oblanceolate or obovate with apex rounded or retuse to vaguely obtuse-acuminate), cymes 1-6 per fascicle (versus cymes mostly 1-2 per fascicle), and flowers numbering 5-9(-14) per cyme (versus cymes mostly 3-5-flowered).The type locality of L. densiflora is also isolated by a distance of c. 150 km from the nearest known locality of L. memecyloides (i.e. near Rantabé in the Antongil Bay region of Toamasina province).

The species was previously illustrated by Jacques-Félix (1985b: tab. 27: 1–4, as L. lutescens).

There is still a lack of precision about the second collecting locality (south of Analamanara between Sambava and Antsirabe Avaratra), but it is evidently close to a remnant forest block called Tsihomanaomby, north of the river Bemarivo and about 3–5 km to the west of the Route nationale 5a (P. Phillipson & J. Razafitsalama, pers. comm.).

Additional material examined. — Madagascar. Prov. Antsiranana: env. S d' Analamanara (près de Tsaratanana), entre Sambava et Antsirabe-Nord, XII.1966, fl., Service Forestier 27175 (BR, G, K, MO, P, TEF, WAG).

= Memecylon melastomoides Naudin in Ann. Sci. Nat., Bot., ser. 3, 18:265.1852.

= Spathandra melastomoides (Naudin) Jacq.-Fél. in Adansonia ser. 2, 18: 228.1978.

Typus : Madagascar: sine loc., s.d., fl., du Petit-Thouars s.n. (holo-: P [P00057571]!; iso-: BR [BR0000006422448]!).

= Memecylon cauliflorum H. Perrier in Mém. Acad. Malgache 12: 209. 1932. Typus : Madagascar. Prov. Toamasina: env. de la baie d'Antongil, c. 100 m, X.1912, fl., Perrier de la Bâthie 2080 (holo-: P [P00057572]!; iso-: P [P00057573]!).

Tree 6–15 m; branchlets 4-winged, the wings greater than 0.5 mm and eventually excoriating, the older branchlets terete and thickened at the nodes. Leaves 3-nerved (the midnerve and pair of lateral nerves clearly visible, prominent on the lower surface of the blade), coriaceous, granular on both faces in dried material; petiole 2 mm ; blades lanceolate to oblanceolate, 5-14 × 2-4 cm, attenuate at the base and decurrent on the petiole, short-acuminate at apex. Cymes umbelliform, solitary or in fascicles of 3–5 at the leafless nodes and the older wood; peduncle 7–15 mm, 4-winged; bracteoles subtending individual flowers very short, truncate, forming a cupule from which emerges the pedicel 2–6 mm. Hypantho-calyx cupulo-patellate, 1.5 × 2 mm; calyx limb truncate to sinuate ; petals pale blue, mostly elliptical to suborbicular, 1.5 × 2 mm, auriculate above the claw 0.5 mm; staminal filaments 3–4 mm, anthers 1 × 0.5 mm, the locules fronto-ventral, connective incurved with a well-developed median gland on the dorsal side, the extremity of the connective subacute ; style 5 mm ; ovary 8-ovuled. Fruit unknown.

Distribution and ecology. — An endemic of low-elevation forests along the eastern coast of Madagascar (Fig. 3), in Antsiranana province (south of Antalaha near Ambohitralanana [Cap-Est]) and in Toamasina province (region of Antongil Bay and recently collected at Pointe à Larrée to the north of Soanierana-Ivongo). The habitat in Pointe à Larrée was described by the collector as “swamp forest”. New localities for L. melastomoides should be sought in the Masoala National Park, particularly the “parcelle détachée d'Andranoanala”, a 13-km² area of littoral forest, flooded forest and swamps that is close to one of the historical collecting localities near Ambohitralanana.

Conservation status. — Lijndenia melastomoides is a poorly known species that had been considered as possibly extinct until its rediscovery at Pointe à Larrée in Nov. 2008.There are just two locations known with any degree of precision, yielding an AOO of 8 km². The location near Ambohitralanana (Cap-Est) was formerly protected in the “Réserve naturelle intégrale no. 2”, but this area was degazetted in 1964. The other location at Pointe à Larrée includes 51 km² of littoral forest and swamp forest and was gazetted as a “Réserve speciale” in 2015. However, the site in recent years has been subjected to threats from logging, wildfires and shifting agriculture, and its status as a protected area is still in the early stages of implementation. Lijndenia melastomoides is thus provisionally assessed as “Critically Endangered” [CR B2ab(iii)] according to the IUCN Red List Categories and Criteria (IUCN, 2012).

Notes. — The conspicuously quadrangular-alate young branchlets of L. melastomoides are unique in the genus. The original material of du Petit-Thouars was labeled “Madagascar ou Ile Maurice” and was supposed by Perrier de la Bâthie (1932, 1951) to be from Mauritius. This is considered very unlikely, however, because all subsequent collections of L. melastomoides are from Madagascar. The species was previously illustrated by Perrier de la Bâthie (1951: fig. 45: 1–8, as Memecylon cauliflorum) and Jacques-Félix (1985b: tab. 27:5–9).

Additional material examined. — Madagascar. Prov. Antsiranana: Distr. Antalaha, C^ton Ambohitralanana, RN II [Masoala], 10.11.1954, fl., Réserves Naturelles 6619 (P). Prov. Toamasina: Pointe à Larrée, forêt Menagisy, 16°48′51″S 49°42′02″E,XI.2008, fl., Nikolov 1812 (G, MO).

= Memecylon lutescens Naudin in Ann. Sci. Nat., Bot., ser. 3, 18: 269. 1852 [nom. illeg.] [non M. lutescens C.Presl].

= Spathandra lutescens (Naudin) Jacq.-Fél. in Adansonia ser. 2,18: 228.1978 [nom. illeg.].

= Lijndenia lutescens (Naudin) Jacq.-Fél. in Bull. Mus. Natl. Hist. Nat., B, Adansonia 7: 44.1985 [nom. illeg.].

Lectotypus (designated here): Madagascar: sine loc., s.d., fl., du Petit-Thouars s.n. (P [P00057566]!; isolecto-: P [P00057567]!; BR [BR000000626115] fragment!).

= Memecylon meeusei H. Perrier in Not. Syst. (Paris) 12: 106.1945. Lectotypus (designated here) : Madagascar. Prov. Toamasina: Soanierana-Ambahoabé, 75 m, 3.XII.1938, fl., Lam & Meeuse 5624 (L [L0009293]!; isolecto-: BR [BR000000626121]!, P [P00057569, P00057570]!, WAG [WAG0002347]!).

Shrub or tree to 4–15 m; branchlets terete ; internodes (0.6-)1-2.5(-6.8) cm. Leaves apparently 1-nerved (only the midnerve clearly visible, the lateral nerves intramarginal and ± obscure), subcoriaceous, finely granular in dried material, on petioles mostly 3–5 mm; blades narrowly elliptic to oblanceolate or obovate, (2.2-)3-5(-6.4) × (1-)1.4-2.2 (-2.8) cm, cuneate at base and gradually narrowed to the petiole, the apex rounded or retuse to vaguely obtuse-acuminate (the acumen if present mostly 2–5 mm); transverse veins not evident or ± faintly visible in dried material, oriented at an oblique angle relative to the midnerve. Cymes umbelliform and mostly 3-5(-8)-flowered, solitary or in fascicles of 2(-3) mostly at the leafless nodes of older branchlets, sometimes also solitary or geminate in the leaf axils, subsessile or on peduncles mostly 1–3 mm (3.5–14 mm in the type material of Memecylon meeusei); each flower subtended by a pair of cymbiform/orbicular, persistent bracteoles fused to form a cupule or involucre from which emerges the pedicel 1–3 mm. Hypantho-calyx cupulo-patellate, 1.5-1.75 × 1.75-2 mm, the margin obscurely 4-sinuate or with calyx lobes slightly triangular; petals white, 1.5-2 × 1.5-2 mm, ungui culate, limb suborbicular with base cordate - auriculate above the claw 0.5 mm; stamens white, the anthers dolabriform, 1-1.5 × 0.5 mm, the anther sacs positioned at the anterior end, connective slightly to strongly incurved by the medially positioned, dorsal oil-gland, prolonged at the posterior end into a subacute beak, filaments slender, 3–4 mm; epigynous chamber deep, smooth (lacking interstaminal partitions); style blue, filiform, 5-9 mm ; ovary 6-8-ovuled. Fruits globose or somewhat asymmetrical, 5–7 mm in diameter, crowned by the persistent calyx c. 1 mm, distinctly 4-toothed or truncate and remotely 4-denticulate.

Etymology. — The epithet memecyloides refers to the genus Memecylon L. with which this species might be confused on account of its apparently uninervate leaves. Sterile specimens of Lijndenia memecyloides bear an especially close resemblance to Memecylon infuscatum Jacq.-Fèl., and the two species occur together in some localities.

Distribution and ecology. — Endemic to Madagascar's eastern coast in Toamasina Province (Fig. 2). Habitat in littoral or sublittoral forest on sand. Elevation from 3 to 75 m above sea level.

Conservation status. — Lijndenia memecyloides is known from six locations and has an EOO of 3,650 km². At least one of the known sites has now been completely deforested (i.e. Mangalimaso to the west of Foulpointe [Mahavelona]). At another site (near Antanambao-Ambodimanga to the south of Manompana) all of the large trees had been removed a year or two prior to my field-work there in Jan. 2007, leaving the area in the early stages of secondary regrowth. However, some occurrences of this species are found within the protected areas network, e.g. the Réserve de Tampolo near Fénérive [Fenoarivo] and Analalava to the west of Foulpointe [Mahavelona], both of these sites gazetted in 2015. Lijndenia memecyloides is thus provisionally assessed as “Vulnerable” [VU B1ab(iii)] according to the IUCN Red List Categories and Criteria (IUCN.2012).

Notes. — The name Lijndenia memecyloides is here taken up for the species to which the illegitimate name L. lutescens was previously applied (Jacques-Félix, 1985b). The present revision also adopts a narrower circumscription of this species in comparison to the earlier treatment of Jacques-Félix (1985b). As presently circumscribed, L. memecyloides includes only the populations in Toamasina province, whilst the populations from Antsiranana and Fianarantsoa provinces are described herein as separate species L. densiflora R.D. Stone and L. acuminata R.D. Stone, respectively. All three of these three species have apparently uninervate leaves and relatively small flowers with white petals. However, L. memecyloides can be distinguished by the combination of leaf-blades mostly oblanceolate to obovate with apex rounded to vaguely short-acuminate, inflorescences 1–2(-3) per fascicle, and peduncles mostly 1–3 mm.

Of the original collection by du Petit-Thouars, there are two sheets in P, both of which are clearly labeled as Memecylon lutescens in Naudin's handwriting. The better of these two sheets has been designated here as the lectotype. In addition there is an “ex herb. Jussieu” sheet [P00057567] that has been labeled as a “Type” but is evidently not part of the original material.

Special mention must be made of the collection Lam & Meeuse 5624 (type of Memecylon meeusei, treated here as a taxonomic synonym of Lijndenia memecyloides). The sheet in L has been designated as the lectotype because it bears a determinavit in Perrier de la Bâthie's handwriting and is of better quality in comparison to the duplicates in other herbaria including P. The material is unusual in having leaf-blades narrowly elliptic with a ± distinct but obtuse acumen 3–8.5 mm. The peduncles are also unusually long (mostly 5–11 mm, rarely to 14 mm), but in other features these specimens agree well with L. memecyloides, and the collecting locality lies well within the geographic range of this species albeit slightly further inland compared to the other known sites which are more-or-less strictly littoral or sublittoral.

The lectotype sheet of L. memecyloides was labeled “Madagascar ou îles Mascareignes,” and Wickens (1976) reported that the original material was collected on Réunion. This is considered very unlikely, however, because all subsequent collections of this species are from Madagascar. Wickens (1976) also erroneously treated Memecylon lutescens Naudin as a taxonomic synonym of M. confusum Blume (an endemic of the island of Réunion). DNA analyses clearly show that the former species is properly placed in Lijndenia whilst the latter belongs to Memecylon s.s. (Stone, 2014; R.D. Stone, unpublished data).

The line drawings of Lijndenia lutescens (≡ L. memecyloides) provided by Jacques-Félix (1985b : tab. 27: 1–4) are actually of L. densiflora R.D. Stone (q.v.). Because this illustration is of material now considered to be a different species, there are no previously published illustrations of L. memecyloides.

Additional material examined. — Madagascar : Prov. Toamasina : Réserve forestière de Tampolo (Fénérive), 9.XII.1989, fl., Evrard 11255-bis (P); limite N de la forêt d'Analalava, 6 km SW de Foulpointe, 17°41′32″S 49°27′28″E, 1.XII.2004, fl., Lehavana et al. 219 (K, MO, P) ; Maroantsetra, Rantabé, 15°43′48″S 49°39′21″E, 19.II.2002, fr., Rabenantoandro & Rolland 897 (MO,TEF); Soanierana-Ivongo, Manompana, forêt sur sables d'Antanambao-Ambodimanga [forêt classée d'Antsiraka], 16°45′40″S 49°42′35″E, 1.II.2003, fr., Rabevohitra et al. 4351 (CAS, G, MO, P, TEF); ibid, loc., Tanambaon'Ambodimanga, 16°46′07″S, 49°42′40″E, 30.I.2004, fr., Rabevohitra 4903 (TEF [the 2^nd sheet of this no. in TEF is Memecylon infuscatum]) ; Soanierana-Ivongo, Manompana, forêt de Fandrarazana, 16°45′10″S 49°43′29″E, 30.I.2004, fr., Rabevohitra & Rakotomamonjy 4913 (CAS, MO, P); env. de PN Mananara-Nord, loc. Ambodihazovola, 27.II.1990, fr., Raharimalala 331 (P); forêt classée de Tampolo, 17°17′S 49°25′E, IV. 1997, fr., Ralimanana et al. 83-bis (G, MO); Tamatave, XII.1948, fl., Service Forestier 1117 (TEF); Tampolo-Tamatave, 27.XI.1951, fl. buds, Service Forestier 4266 (MO, P,TAN,TEF); Distr. Fénérive, C^ton Ampasina, Tampolo (parcelle B.3), 13.1.1956, fl., Service Forestier 15332 (K, MO, P, TEF) ; ibid, loc., Jard. Bot. no. 21,17.XII.1956, fl., Service Forestier 16476 (MO, P,TEF); forêt de Mangalimaso, W Foulpointe, 23.XI.1962, fl., Service Forestier 22086 (K, L, MO, P,TEF, WAG); S of Fandrarazana, E side of road to Antanambao-Ambodimanga, 16°45′29″S 49°42′58″E, 19.1.2007, ster., Stone et al. 2600 (CAS, P [05207162],TAN). Sine loc. : sine loc.,s.d.,fl., Aublet s.n. (P).

Typus : Madagascar. Prov. Toamasina: Antanambé, S de Mananara, XI. 1964, fl., Service Forestier 23755 (holo-: P [P00057574]!; iso-: G [G00443616]!, K [K000230002]!, MO-4373215!, P [P00057575]!,TEF [TEF000310]!, WAG [WAG0027198]!).

Shrub or small tree; young branchlets terete, flexuous. Leaves 3-nerved (principal nerves slightly visible on the upper surface, moderately salient on the lower, the pair of lateral nerves evanescent towards the apex), subcoriaceous, yellowish green and granular on the lower surface in dried material; petiole 3 mm ; blades elliptic to elliptic-lanceolate, up to 5.5 × 2 cm, cuneate at base, distinctly acuminate at apex (the acumen obtuse and ± apiculate). Cymes numbering 3–13(-18) in fascicles at the nodes of the trunk, forming an inflorescence 3–4 cm in diameter and totaling some 60 flowers; each cyme with a slender peduncle 5–15 mm, directly umbelliform or formed of several umbellules each grouping 6–9 pedicellate flowers; bracteoles concrescent at their base, the margins free, hyaline, truncate, forming an involucre at the base of the pedicel 5–7.5 mm. Hypantho-calyx cupulo-patellate, 2×3 mm, the margin membranous, at first 4-lobed in bud, then only sinuate and minutely 4-toothed at anthesis; epigynous chamber smooth, style 6–7 mm; petals blue, membranous, semi-ovate, auriculate above the claw, 2.5 × 3 mm; staminal filaments 5 mm, anthers 2×1 mm, anther-sacs fronto-ventral, connective conical, slightly incurved by a median gland 1/3 the length of the connective; ovary 8-ovuled. Fruit unknown.

Distribution and ecology. — The type and only known collection of L. ramiflora was made in the coastal region near Antanambé in central Madagascar′s Toamasina province (Fig. 3). According to the collector, the site is on lateritic soil and the habitat was presumably in sublittoral forest.

Conservation status. — Lijndenia ramiflora is known from a single location with an AOO of 4 km². The coastal forests in the type region have already been destroyed or reduced to small remnants, and L. ramiflora was not found during two days of field-work by the present author from Antanambé southward to Manompana (on 17–18 Jan. 2007). Given the extensive loss of habitat and the fact that L. ramiflora has not been seen in more than 50 years, it is quite possible that the species is already extinct, although more exhaustive surveys would be needed to establish this beyond a reasonable doubt. Lijndenia ramiflora is thus provisionally assessed as “Critically Endangered” [CR B2ab(iii)] according to the IUCN Red List Categories and Criteria (IUCN, 2012).

Notes. — Lijndenia ramiflora is distinctive in producing inflorescences in dense fascicles lower down on the trunk (whilst in the other Lijndenia species the inflorescences appear mostly in fascicles at the leafless nodes of older branchlets i.e. just below the leaves). The species was previously illustrated by Jacques-Félix (1985b : tab. 29: 5–9).

= Memecylon roboreum Naudin, Ann. Sci. Nat., Bot., ser. 3,18: 268.1852.

= Spathandra roborea (Naudin) Jacq.-Fél., Adansonia ser. 2,18: 228.1978.

Typus : Madagascar: sine loc. [env. de Tamatave, fide Perrier de la Bâthie, 1951: 300], s.d., fl. buds, Chapelier s.n. (holo-: P [P00057576]!; fragment: BR [BR000000626105]!).

= Memecylon viguierianum H. Perrier, Mém. Acad. Malgache 12 : 219. 1932. Typus : Madagascar. Prov. Toamasina : côte orientale, Tampina, près des lagunes, XI.1920, fl., Perrier de la Bâthie 13293 (holo- : P [P00057577]!; iso-: P [P00057578,00057579]!).

Shrub or small tree 2–6 m; young branchlets terete, stout. Leaves apparently 1-nerved (the midnerve visible on the upper surface, thick but not salient on the lower; the pair of intramarginal nerves obscure but ± visible towards the base on both surfaces), thickly coriaceous, smooth or slightly granular in dried material; petiole 2–6 mm, thick; blades mostly obovate, 4–7(-8.5) × 2–4(-5.7) cm, mostly cuneate at base and rounded to retuse or emarginate at apex; transverse veins salient in the upper part of the leaf, orientated at a somewhat oblique angle relative to the midnerve. Cymes solitary or fascicled on the leafy or leafless nodes; peduncle thick, flattened, 0.5–3 mm; immediately umbelliform and 7-15-flowered; bracts fleshy, adherent at their base; bracteoles 1 mm with free margins, membranous, truncate; pedicel 3–5 mm. Hypantho-calyx cupulo-patellate, 2–2.5 × 2.5–3 mm, calyx lobes triangular, 0.7 × 1 mm; petals pale blue, unguiculate, limb membranous, ± orbicular, 2.5–3 × 2–3 mm, base cordate to auriculate, claw 1.5 mm, thick, linear or dilated towards the base of the limb; stamens equal or the epipetalous ones slightly longer (filaments 5–7 mm), anthers 1–1.5 × 0.5 mm, anther sacs frontal, connective incurved with the gland slightly anterior, extremity acute; style 12 mm. Fruit globose, 8 mm in diameter, green turning dark purple at maturity; calyx lobes persistent.

Distribution and ecology. — An endemic species of the littoral forest along Madagascar's eastern coast, in Toamasina province from near Ambila-Lemaitso northwards to Foulpointe (Fig. 3).

Conservation status. — Lijndenia roborea seems to be a rather common species but with a very limited area of distribution. It is known from four locations (none within a formally protected area) and has an EOO of 420 km². One of the known locations (Ambila-Lemaitso) has been recommended for protected status, and another site (Vohibola) where L. roborea is expected to occur has been similarly recommended (Consiglio et al., 2006). Lijndenia roborea is thus provisionally assessed as “Endangered” [EN B1ab(iii)+B2ab(iii)] according to the IUCN Red List Categories and Criteria (IUCN, 2012).

Notes. — This species was previously illustrated by Perrier de la Bâthie (1951 : fig. 48: 1–4, as Memecylon viguierianum) and Jacques-Félix (1985b : tab. 28: 1–5).

Because the leaves of Lijndenia roborea are so thickly coriaceous, the ramiform sclereids are not evident as a granular surface texture in dried material (unlike other Lijndenia spp. in which this finely granular texture is usually present).The fruits are edible and delicious when ripe.

In the Flore de Madagascar (Perrier de la Bâthie, 1951), the name Memecylon subcuneatum H. Perrier (1932) was considered to be a taxonomic synonym of M. roboreum (≡ Lijndenia roborea), but this would seem to be an error as a reexamination of the holotype of M. subcuneatum (Perrier de la Bâthie 6479, P [P00062708]) indicates it is properly placed in Memecylon s.s.

Additional material examined. — Madagascar. Prov. Toamasina : near lake S of Ambila-Lemaitso, 19.1.1986, fr., Dorr et al. 4587 (K, MO, TAN); env. d' Ambila-Lemaitso, 14.XI.1986, fl., Le Thomas 105 (P); Foulpointe, IV.1986, fr., Rakotozafy 2048 (MO,TAN); Ambila-Lemaitso, just N of railroad bridge, W of pangalane (canal), 18°51′S 49°08′E, XI.1988, fl., Schatz et al. 2417 (K, MO, P, TAN) ; ibid, loc., 28.I.1993, fr., Schatz et al. 3434 (BR, CAS, MO, P, TAN); Ambila-Lemaitso, 2.II.1951, fr., Service Forestier 2893 (P, TAN); ibid, loc., 26.XII.1963, fl. buds, Service Forestier 22755 (K, MO, P, TEF); ibid, loc., 14.XII.1967, fl., Service Forestier 28040 (K, MO, P, S, TEF); 7.5 km S d′Ambila-Lemaitso, forêt d'Andavakimena, près du lac d'Andobobe, 18°54′S 49°07′20″E, 14.XI.2001, fl. & immature fr., Stone et al. 2386 (CAS, P, TAN) ; N of Ambila-Lemaitso along pangalane, Andrasoabe forest near Ampanotoamaizina, 18″42′03″S 49″12′11″E, 13.II.2008, fr., Stone et al. 2670 (CAS, G, K, MO, P, TAN).

Typus : Madagascar. Prov. Fianarantsoa: entre Farafangana et Manombo, 8.XII. 1964, fl. past anthesis & imm. fr., Service Forestier 23933 (holo-: P [P00057580]!; iso-: P [P00057581]!,TEF!).

Large shrub; young branchlets terete. Leaves apparently 1-nerved (the midnerve finely impressed on the upper surface, faintly prominent below; intramarginal nerves slightly visible below, evanescent towards the apex), subcoriaceous, yellowish green, dull, granular on both surfaces in dried material; petiole 5–8 mm; blades elliptic-lanceolate, up to 9 × 3.8 cm, cuneate at the base, shortly obtuse-acuminate at the apex. Cymes umbelliform, borne terminally on the branchlets or solitary to geminate in the leaf axils; peduncle 10–15 mm; heads subtended by a pair of triangular bracts and with a pair of concrescent, truncate-margined, hyaline bractlets subtending each pedicel 4–5 mm. Flowers not seen. Fruits hemispheric in early development, 1.5–2 mm in diameter, crowned by the persistent calyx 1 × 2.5–3 mm, the margin sinuate and minutely 4-toothed; mature fruit unknown.

Distribution and ecology. — An endemic of southeastern Madagascar, in Fianarantsoa province south of the coastal town of Farafangana (Fig. 3). The type and only known collection was made in remnants of sublittoral forest, on laterite weathered from basalt.

Conservation status. — Lijndenia terminalis is known from a single location and has an AOO of 4 km². At the time of the type collection in 1964, the coastal forests in the region of Farafangana had already been severely fragmented by anthropogenic activities. Today, these forests have almost completely disappeared (R. D. Stone, personal observation). Forested habitats on basaltic soils still remain in the Réserve spéciale de Manombo, but L. terminalis was not found there despite two days of searching by the present author on 22–23 Nov. 2001. Given the severe loss of habitat and the fact that L. terminalis has not been seen in more than 50 years, it is quite possible that the species is already extinct, although more exhaustive surveys would be needed to establish this beyond a reasonable doubt. Lijndenia terminalis is thus provisionally assessed as “Critically Endangered” [CR B2ab(iii)] according to the IUCN Red List Categories and Criteria (IUCN, 2012).

Notes. — The cymes borne terminally on the branchlets and at the uppermost leafy nodes are quite distinctive of this species. However, mounted on the Isotype sheet in P [P00057581] there are also two densely fascicled, trunciflorous inflorescences very similar to those of L. ramiflora (q.v.). In fact, after a close reexamination I cannot find any differences between the two. Moreover, the axillary and terminal inflorescences of P00057581 have young, developing fruits like those of the Holotype sheet [P00057580] whilst the two trunciflorous inflorescences have flowers ranging from the bud stage to anthesis and past anthesis. These observations indicate that the trunciflorous inflorescences found on the isotype sheet of L. terminalis are really from the type collection of L. ramiflora (Service Forestier 23755) and were placed in error with P00057581. It would thus seem that the original description and illustration of the flowers and floral parts of L. terminalis (Jacques-Félix, 1985b : 42 8c tab. 29:1–4) were erroneously based on material taken from L. ramiflora.