1. Tiges à pubérulence grise; feuilles à marge entière; inflorescences à une fleur; bractées de l'inflorescence disposées en 14 ou 15 paires décussées et fortement imbriquées; pédicelles velus à indument doré; extérieur du calice densément soyeux et doré P. orientalis

1a. Tiges glabres ou glabrescentes; feuilles à marge crénuléeserretée, parfois épineuse, rarement entière; inflorescences avec 2 à 10 fleurs; bractées de l'inflorescence pas distinctement décussées-imbriquées; pédicelles glabres ou glabrescents ou faiblement à modérément brun-pubérulents; extérieur du calice avec un indument épars apprimé 2

2. Feuilles étroitement elliptiques, avec un rapport longueurlargeur dépassant 3:1; pétales 4, linéaires, de 4,5 à 6,5 mm de long P. razakamalalae

2a. Feuilles elliptiques, avec un rapport longer-largeur généralement inférieur à 3:1; pétales 6 ou 8 (ou 9), obovales, de 11 mm de long ou plus 3

3. Pétales 8 (ou 9), 17–29 mm de long; fruit obovoïde, jusqu'à 43 mm de haut et 32 mm de diamètre P. grandis

3a. Pétales 6, 11–14 mm de long; fruit sphérique ou ovoïde, 7–17 mm de haut et 7–14 mm de diamètre 4

4. Bractées de l'inflorescence triangulaires à ovales, densément soyeuses à l'anthèse, clairement disposées en groupes le long d'un axe allongé, séparées les unes des autres par des entre-noeuds visibles; extérieur du calice portant à la base une touffe circulaire dense de trichomes érigés P. calcicola

4a. Bractées de l'inflorescence aciculaires à étroitement triangulaires, faiblement soyeuses à l'anthèse, groupées sur un axe court, cachant presque toujours les entre-noeuds; extérieur du calice sans une touffe circulaire de trichomes à la base P. hildebrandtii

Tree to 15 m tall, 18 cm DBH. Stems glabrous. Stipules 4 × 1 mm, linear to narrowly triangular, caducous. Leaves (3.7-) 9.6-14.7 × (2.7-)2.9-5.9 cm, elliptic to narrowly elliptic, coriaceous, glabrous on both surfaces, base acute to cuneate, margins with 8 to 10 crenulate-serrate teeth, apex acuminate, the acumen to 2 cm, midrib slightly raised above, raised below, glabrous, venation semicraspedodromous, 6 to 9 secondary veins per side, slightly raised on both surfaces, tertiary venation distinctly raised on both surfaces; petioles 2–4 mm, glabrous. Inflorescences axillary, subtended by a pair of narrowly triangular, slightly concave bracts, 2 × 1.5 mm, pseudo-umbellate, 4- or 5-flowered, the peduncle/rachis not visible at anthesis, ca. 1 mm long, ca. 2 mm in diam., the peduncle and rachis elongating post anthesis and into fruit such that the internodes between flowers and their subtending bracts become distinctly visible, the peduncle 4 mm long, 2 mm in diam., the rachis 2.5 mm long. Pedicels subtended by 3 overlapping triangular to ovate-concave, keeled bracts (2 inner and opposite, 1 outer), each 2-2.5 × 1.5 mm, moderately to densely golden tomentose outside, glabrous inside, above which sits a distinct torus of sparse trichomes surrounding the base of the pedicel; pedicels 23–50 mm at anthesis, slender, to 1 mm in diam., crowned by a flange, 1 mm tall, 5 mm in diam., initially with sparse appressed white indumentum, glabrescent by anthesis; pedicels becoming stout in fruit, 1.5 mm in diam. at base, increasing to 2.5 mm at apex. Calyx in bud 9-11 × 4.5 mm in diam., ellipsoid, base truncate, apex acute, entire, calyptriform and tearing irregularly, caducous, thin and tissue-like, with sparse appressed white indumentums outside, glabrous inside. Petals 8 (or 9), of variable size and shape, pale lavender in vivo, the larger ones to 29 × 7-11 mm, spatulate-obovate, sometimes deeply cleft and therefore bilobed, distinctly clawed, the claw 4–5 mm limb, tissue-like with visible venation, glabrous outside, moderately densely beige lanate inside, indumentum persisting towards the rounded apex, the acumen sometimes blunt, the smaller petals to 17 × 4 mm, linear, glabrous outside, moderately densely beige lanate inside, all petals rapidly caducous. Stamens 25 to 30, arranged in two series united into a single ring at their base; filaments 3.5–6.5 mm long, densely white lanate; anthers 4.5-6.0 × 0.5 mm, yellow in vivo. Ovary not seen. Fruit a tardily dehiscent capsule, to 43 mm tall, 32 mm in diam., obovoid, glabrous, smooth “in vivo”, verrucose when dried, crowned by the blunt apiculate stylar remnant, 1–4 mm; seed not seen.

Notes. — Prockiopsis grandis is known only from two gatherings made ca. 4 km apart from one another at 145 and 310 m elevation on the northern and southern margins of the forêt d'Andranomatavy on the Ampasindava peninsula, which straddles the dry and subhumid bioclimatic zones of Cornet (1974; see Schatz, 2000). The forest encompasses an area of isolated hilly topography up to 668 m elevation in the subhumid zone, and is described as «Forêt dense humide sempervirente » on the label of Ammann & al. 489, the gathering from the northern margin of the forest. The remaining forests in the northern part of the Ampasindava peninsula have been classified by Humbert (1965) as «Forêt ombrophile du Sambirano», a region with a high level of local endemism to which P. grandis is a further addition. The new species can easily be distinguished from P. hildebrandtii, with which it is sympatric, as well as from the other member of the genus for which fruit is known (P. calcicola), by its fruit that is over two times larger than those of P. calcicola and P. hildebrandtii, and by its more numerous petals (8 or sometimes 9 versus 6 in P. calcicola, P. hildebrandtii, and P. orientalis and 4 in P. razakamalalae), which are also larger (17 to 29 mm long versus 4.5 to 16 mm long in the other four species).

Conservation status. — The forêt d'Andranomatavy encompasses at most 40 km2 on the Ampasindava peninsula, some of which is fragmented and degraded as a result of human activities. Although a conservation management plan is currently being formulated for the forest, in the absence of effective protection it is unlikely that the forest will persist beyond 3 generations of P. grandis (ca. 45 years). Thus, its risk of extinction can be assessed as “Critically Endangered” (CR A3c) following the IUCN Red List Categories and Criteria (IUCN, 2012).

Paratypus. — MADAGASCAR. Prov. Antisiranana: Ampasindava, forêt d'Andranomatavy, 13°38′22″S 47°59′09″E, 310 m, 15.XII. 2009, fr., Ammann, Madiomanana & Tahinarivony 489 (G, K, MO, P, TEF, WAG).

Tree to 10 m tall. Young stems with sparse, minute appressed indumentum, soon glabrescent. Stipules 0.75 × 0.2 mm, narrowly triangular, glabrous, caducous. Leaves 3.1-7.3 × 0.9-2.0 cm, narrowly elliptic, subcoriaceous, glabrous on both surfaces, base narrowly cuneate, margins with 5 to 8 crenulate-serrate teeth, apex narrowly acute, the acumen rounded, midrib flat above, raised below, glabrous, venation semicraspedodromous, 8 to 10 secondary veins per side, slightly raised on both surfaces, tertiary venation distinctly raised on both surfaces; petioles 3.5–6 mm, with sparse, minute appressed indument, glabrescent. Inflorescences axillary, pseudo-umbellate, 4- to 7-flowered, the peduncle at anthesis 2.5–3 mm long, 1 mm in diam., the rachis at anthesis 0–2.5 mm, peduncle and rachis with dense, light tan, appressed indument. Pedicels subtended by 3 overlapping, narrowly triangular, concave, minute bracts (2 inner and opposite, 1 outer), each 0.5-1 × 0.5 mm, densely tan puberulent outside, glabrous inside, above which sits a distinct torus of dense trichomes surrounding the base of the pedicel; pedicels 16–25 mm, slender, to 0.5 mm in diam., with sparse to moderate, appressed tan indumentum. Calyx in bud 4.5-6 × 1.5-2 mm in diam., ellipsoid, base truncate, apex acute to rounded, entire, calyptriform and tearing irregularly, persistent through anthesis, thin and tissue-like, with sparse appressed tan indumentums outside, glabrous inside. Petals 4, equal, 4.5-6.5 × 0.7-1.1 mm, linear, glabrous outside, densely light ferruginous lanate inside, caducous. Stamens 9 to 12; filaments 1.5–4 mm long, sparsely light ferruginous lanate; anthers 2-2.8 × 0.5 mm. Ovary 2– mm tall, 1.5–2 mm in diam., ellipsoid, nearly black “in seco”, with very sparse, appressed white trichomes, style 3–3.6 mm, stigma bifid or trifid, lobes 0.2 mm. Mature fruit not seen.

Etymology. — The species epithet honors our colleague Richard Razakamalala, whose sharp eyes have spotted many novelties that are contributing significantly to our ever-increasing knowledge of the Malagasy flora. Our colleague Charles Rakotovao, who collected the type specimen with Richard, first pointed out the possible novelty that we describe here and joins us as a co-author of this species.

Notes. — Prockiopsis razakamalalae is known only from a single gathering in the tiny fragments of the forêt d'Ambatotstirongorongo ca. 18 km west of Fort Dauphin in the transitional area between the humid and subarid bioclimatic zones of Cornet (1974; see Schatz, 2000). It can be easily distinguished from all other members of the genus by its narrowly elliptic, crenulate-serrate leaves with a length to width ratio of greater than 3:1, and by its four small, linear petals.

Conservation status. — The forêt d'Ambatotstirongorongo was briefly inventoried as a potential offset site for the QMM mining project, but currently is unprotected. Ongoing threats to the remaining tiny fragments of forest from human-set fires and cutting for fuelwood render the likelihood of persistence of P. razakamalalae extremely low over the next 3 generations (ca. 45 years). Thus, its risk of extinction can be assessed as “Critically Endangered” (CR A3c) following the IUCN Red List Categories and Criteria (IUCN, 2012).