Craterispermum cervicorne De Block & Randriamb., 2015

De Block, Petra & Randriamboavonjy, Tianjanahary, 2015, Three new species of Craterispermum (Rubiaceae) from Madagascar, Phytotaxa 206 (1), pp. 79-89 : 86-88

Craterispermum cervicorne De Block & Randriamb. , sp. nov. Fig. 3 .

Type: — MADAGASCAR. Province Fianarantsoa: Karianga, district Farafangana, 22° 22’ S, 47° 26’ E, 7 October 1926, Decary 5495 (holotype P, isotypes BR, G, K, MO, UPS).

Differs from all other Madagascan Craterispermum species by the large, lax, antler-shaped inflorescences, the lateral inflorescence axes of which are 1–5 cm long, with the central inflorescence axis usually ca. 0.5 cm long or rarely up to 5 cm long

Tree, 3–15 m tall, dbh 6–30 cm, more rarely shrub, 4–6 m tall; vegetative and generative parts glabrous; older branches greyish brown, somewhat corky; younger branches greenish or greenish brown, smooth. Stipules ca. 3 mm long, keeled, not persistent on older branches, awn ca. 0.5 mm long. Leaves petiolate; petioles 0.5–2.5 cm long, canaliculate; leaf blades elliptic or obovate, rarely broadly elliptic, 5–14 x 2.7–5.5 cm, coriaceous, drying golden, yellowish or greenish brown, often somewhat discolourous with lower surface paler; apex acuminate, acumen 2–8 mm long; base decurrent; margin revolute; midrib prominent on both leaf surfaces, raised below, impressed above; secondary nerves prominent on both surfaces, raised below, impressed above, 7–12 on each side of the midrib; higher order venation prominent on both surfaces, raised or not raised below, impressed above, usually paler than blade below (when dry). Inflorescences supra-axillary, attached 3–5 mm above node, many-flowered, pedunculate, lax double scorpioid cyme; peduncle laterally compressed, widened distally, 1–3 cm long; lateral inflorescence axes 1–5 cm long, usually monochasial (2 flowers and 1 axis per node) or rarely dichasial; central inflorescence axis usually reduced (ca. 0.5 cm long), more rarely as long as the lateral axes (e.g. in 13585-SF); bracts broadly triangular and vaulted, 1–2 mm long, tip acute to shortly acuminate, margin sometimes sparsely beset with colleters. Flowers sessile to shortly pedicellate with pedicels 0–5 mm long, 5-merous, flower bud rounded; bracteoles broadly triangular or broadly ovate, ca. 1 x 1.5 mm, tip acute or rounded, margin often sparsely beset with colleters; calyx tube 1–1.5 mm long, inner surface glabrous but sometimes with small groups of colleters 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; corolla white; corolla tube narrowly cylindrical but widening somewhat at the throat, 4–7 mm long, inner surface densely pubescent in upper half and throat; corolla lobes 2.5–4 x 1.5–2 mm, inner surface pubescent with long erect hairs at the base, pubescence continuing sparsely along the midrib higher up, tip acute with short adaxial subapical spike-like protuberance, margin somewhat thickened; anthers 1.5–2 mm long; stigmatic lobes 0.5–1.5 mm long; ovary cup-shaped, 0.7–1 mm long, 2-locular, each locule containing a solitary pendulous ovule. Longistylous flowers: stamens only partly exserted, sessile; style and stigma 5.5–10 mm long, exserted for 1.5–5 mm from corolla tube. Brevistylous flowers: stamens exserted, filaments 1.5–2 mm long; style and stigma 4.5–7 mm long, included in corolla tube. Mature fruits unknown.

Etymology:—The species is named for the large inflorescences that resemble the antlers of a stag.

Distribution:—Only known from the Vatovavy-Fitovinany, Atsimo-Atsinanana and Haute Matsiatra Regions in southeastern Madagascar. Fig. 4 .

Habitat:—Humid lowland forest. Elev.: 20– 900 m.

Phenology:—Flowering: October–November; Fruiting: immature fruits in October–November.

Vernacular Names:—hazomamy.

Uses:—Wood is used for construction and as fire wood.

IUCN status:—Vulnerable: VU B1ab(i); B2ab(ii,iii). The extend of occurrence (EOO) of C. cervicorne is 8,494.83 km 2, and its area of occupancy (AOO) is 839,00 km 2 using a cell width of 7 km. The species occupies 10 cells and AOO indicates that it is distributed in nine subpopulations. It occurs in two protected areas, Manombo and Ivohibe, and one protected forest located in Manakara. The subpopulations outside the protected areas occur in remnant forests, which are severely threatened by destruction. In addition, the species has a low density: over a period of one hundred years only thirteen specimens were collected: ten specimens were collected before 1960, only three after 1990.

Additional specimens examined (paratypes):— MADAGASCAR. Province Fianarantsoa: district Vohipeno, Labolakevo , Ambolonondry , 40 m, 22° 21’ S, 47° 50’ E, 18 October 1952, coll. ignot. 6370-SF ( BR, P, TEF) ; canton et district Manakara, forêt de Manakara , N du terrain d’aviation, 22° 13’ S, 47° 59’ E, 17 November 1952, coll. ignot. 6575-SF ( P, TEF) ; canton et district Manakara, forêt d’Ivakoany , 22° 3’ S, 47° 54’ E, 22 October 1954, coll. ignot. 13573-SF ( BR, P, TEF) ; canton Manakara, district Manakara, Analamitily , 22° 13’ S, 47° 59’ E, 27 November 1954, coll. ignot. 13585-SF ( BR, P, TEF) ; canton et district Manakara, Belambo , 22° 46’ S, 47° 31’ E, 14 February 1955, coll. ignot. 13602-SF (K P, TEF) ; canton et district Farafangana, lieu JB n° 16, village le plus proche Manombo , 23° 2’ S, 47° 44’ E, 17 November 1955, coll. ignot. 16158-SF ( BR, P, TEF) ; canton et district Manakara, Belambo, village plus proche Marohala , 22° 46’ S, 47° 31’ E, 29 October 1955, coll. ignot. 16234-SF ( P, TEF) ; réserve spéciale de Manombo , parcelle 1, 20–50 m, 23° 0’ 35” S, 47° 43’ 15” E, 26 October 2000, Hoffmann, Ranaivojaona, Ralimanana, Richard & Ramaharitra 318 ( BR, K, TAN) ; Bas Matatana , 22° 20’ S, 47° 40’ E, August 1911, Perrier de la Bâthie 3975 ( P) ; commune Farafangana, district Vondrozo, Ampasipotsy , 6 km from Madiorano to Vohibe (RN27), 589 m, 22° 47’ 9” S, 47° 12’ 17” E, 23 October 2006, Ranarivelo, Ranaivojaona, Rakotoarinivo & Rajaonarison 353 ( BR, K, MO) ; Tanjongato, canton et district Manakara , 22° 6’ S, 47° 57’ E, 20 October 1952, Razafimamonjy 52 (as 52-R-118) ( P, TEF) ; trail S of Morafeno, starting ca. 5 km E of Ranomafana on RN 25, between Morafeno and Ambinanindranofotaka and forest N of Ambinanifotaka, along bank of Faraony river , 600–900 m, 21° 20’ S, 47° 30’ E, 4 October 1996, Turk, Randrianasolo, Randrianjatovo, Marolahy & Welton 654 (K, MO, TAN).— Locality unknown: s. loc, s. dat. Baron 2590 (K, P) .

Figures

FIGURE 3. Craterispermum cervicorne. A. Flowering branch. B. Stipules. C. Detail of higher order venation. D. Inflorescence (corollas fallen). E. Bracteole, ovary and calyx. F. Brevistylous flower with separate style and stigma. G. longistylous flower. Drawn by Marijke Meersman. Based on Decary 5495 (A–F) and Ranarivelo et al. 353 (G).

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