Craterispermum puffianum De Block & Randriamb., 2015

De Block, Petra & Randriamboavonjy, Tianjanahary, 2015, Three new species of Craterispermum (Rubiaceae) from Madagascar, Phytotaxa 206 (1), pp. 79-89 : 84-86

Craterispermum puffianum De Block & Randriamb. , sp. nov. Fig. 2 .

Type: — MADAGASCAR. Province Toamasina: partie Sud-Est de la Réserve Naturelle Intégrale de Zahamena, bord de la rivière Namarafana, Miarinarivo, Vavatenina, 420 m, 17° 43’ 47” S, 48° 58’ 45” E, 22 October 1994, Randrianjanaka & Zafy 228 (holotype MO, isotypes K, P).

Differs from C. motleyanum by its narrowly obovate leaves (vs. obovate or broadly obovate) with mucronate apices (versus apex acuminate with acumen 1–5 mm long), obscure higher order venation on both leaf surfaces (vs. prominent on both surfaces) and shorter peduncles (1–2 mm long vs. 2–14 mm long).

Shrub, 1.5–3 m tall; vegetative and generative parts glabrous; internodes short; older branches brown, corky; younger branches brown or pale brown, often with weak decurrent ridge. Stipules 1.3–2.5 mm long, keeled, persistent, awn 0.1–0.2 mm long. Leaves petiolate; petioles 0.4–1 cm long, canaliculate; leaf blades narrowly obovate, 3–7 x 0.8–2 cm, coriaceous, drying golden, yellowish or yellowish brown; apex mucronate; base decurrent; margin revolute; midrib prominent on both leaf surfaces, raised below, impressed above; secondary nerves subprominent on both surfaces, somewhat raised below, impressed above, 4–7 on each side of the midrib; higher order venation obscure to invisible on both surfaces. Inflorescences axillary or somewhat supra-axillary (then inserted ca. 1 mm above node), usually 3- flowered (rarely 5-flowered), pedunculate, compact cyme; peduncle stout, laterally compressed, widened distally, 1–2 mm long; bracts broadly triangular and vaulted, ca. 1.5 mm long, tip acute to shortly acuminate, margin sometimes sparsely beset with colleters. Flowers sessile, 5-merous, flower bud rounded; bracteoles broadly ovate, ca. 1 x 1.5 mm, tip acute to acuminate, margin often sparsely beset with colleters; calyx tube 0.5–1 mm long, inner surface glabrous but groups of colleters present below the sinuses of the calyx lobes; calyx lobes triangular, 0.5–0.8 mm long, inner surface glabrous, tip acute and tipped by colleter, margin often sparsely beset with colleters; corolla white; corolla tube narrowly cylindrical but widening somewhat at the throat, 6.5–8 mm long, inner surface densely pubescent in upper half and throat; corolla lobes 3–3.5 x 1.5–2 mm, pubescent with long erect hairs, tip acute with short adaxial subapical spike-like protuberance, margin somewhat thickened; anthers ca. 2 mm long; stigmatic lobes 1–1.5 mm long; ovary cup-shaped, 2-locular, each locule containing a solitary pendulous ovule. Longistylous flowers: inner surface of corolla lobes densely pubescent all over; stamens completely included in corolla tube, filaments <0.5 mm long; style and stigma 10–11 mm long, exserted for 2–3 mm from corolla tube; ovary ca. 1 mm long. Brevistylous flowers: inner surface of corolla lobes densely pubescent in lower half, sparsely pubescent in upper half; stamens exserted, filaments ca. 1.5 mm long; style and stigma 5–6 mm long, included in corolla tube; ovary ca. 0.5 mm long. Fruits subsessile, subglobose and somewhat asymmetrical, ca. 5 x 4 mm, green turning violet at maturity, one-seeded; calyx persistent; seed ca. 4 x 3.5 mm.

Etymology: —The species is named in memory of Christian Puff, a great Rubiaceae researcher, who worked both in Africa and Asia, and who revised several genera of Madagascan Rubiaceae , such as Alberta Meyer (1838: 258) , Anthospermum Linnaeus. (1753: 1058) , Paederia Linnaeus (1767: 52) .

Distribution: —Only known from the Alaotra-Mangoro Region in Eastern Madagascar, notably from Zahamena National Park and its close surroundings. Fig. 4 .

Habitat: —Forest, often on river banks, on alluvial soil. Elev.: 400–1200 m.

Phenology: —Flowering: October; Fruiting: January.

Vernacular names: —masindranonandroana (Betsimisaraka).

Uses: —Wood is used as fire wood.

IUCN status: —Endangered: EN B1ab(i); B2ab(ii,iii,iv). The extend of occurrence (EOO) of C. puffianum is 856.60 km 2 and its area of occupancy (AOO) is 20 km 2 using a cell width of 2 km. The species is distributed in five subpopulations, three of which are conserved by a single protected area, Zahamena Ankeniheny. The major threat for this species is habitat loss, not only outside Zahamena but also inside this park, which is subject to traditional mining. In addition, this humid forest species has a low density: only seven herbarium collections were collected over a period of 68 years. Only one specimen dates from after 1990.

Additional specimens examined (paratypes):— MADAGASCAR. Province Toamasina: Canton Manakambahiny Est, district Ambatondrazaka , Ambinanisatandrazana , Sahamalaza , bas fond au bord de rivière, 18° 1’ S, 48° 26’ E, 20 October 1966, Capuron 26160-SF ( P, TEF) ; Ampitanonoka à Fotsialalana , sentier plus loin que le chûte, 1200 m, 17° 47’ S, 48° 56’ E, 19 January 1945, Cours 2471 ( P, TAN) ; sentier au N de Sahamalaza pénétrant dans la RN III jusqu’à l’enclave, S/P d’Ambatondrazaka , 17° 50’ S, 48° 25’ E, 20 October 1966, Jacquemin H 189J ( P) ; sentier au N de Sahamalaza pénétrant dans la RN III jusqu’à l’enclave, au bord du fleuve Onibe, S/P d’Ambatondrazaka , 17° 50’ S, 48° 25’ E, 20 October 1966, Jacquemin H 193J ( P) ; canton Manakambahiny-Est, district Ambatondrazaka, Mitanonoka , 18° 1’ S, 48° 26’ E, 21 January 1963, Laibozaka 12607-RN ( TEF) ; Sahamalaza, long du fleuve d’Onibe , 17° 43’ S, 48° 49’ E, 20 October 1966, Rakotozafy 716 ( TAN) .

Figures

FIGURE 2. Craterispermumpuffianum. A. flowering branch.B. Stipules.C. Inflorescence.D. Bracteoles, ovaryand calyx.E. Brevistylous flower with separate style and stigma. F. Longistylous flower with indication of anther position and pubescence of inner surface of corolla tube. G. Fruit. H. Seed. Drawn by Marijke Meersman. Based on Randrianjanaka & Zafy 228 (A–D, F), coll. ignot. 20160-SF (E) and Cours 2471 (G–H).

FIGURE 4. Distribution map of Craterispermum motleyanum (pentagon), C. puffianum (square) and C. cervicorne (triangle).