5. Micronychia striata Randrian. & Lowry, sp. nov.

(Fig. 6)

Haec species quoad laminam foliarem utrinque glabram 8-15 cm longam apice plerumque acutam usque acuminatam, in medio nerviis secundariis inter se 12 cm distantibus ad Micronychiam benono maxime accedit, sed ab ea foliis oppositis, petiolo 26 mm longo, infructescentia 2.5-5 cm longa atque fructu manifeste striato distinguitur.

TYPUS. — Madagascar. Prov. Antsiranana, Andapa, Doany, Andranomilolo, forêt dense humide de moyenne altitude située au pied du sommet d’Anjanaharibe “ Nord ”, 14°28’55”S, 49°32’43”E, 1098 m, 24.XI.2006, fr., Rakotovao et al. 3518 (holo-, MO!; iso-, P!, TAN!).

PARATYPES. — Madagascar. Prov. Antsiranana, massif de l’Anjanaharibe (pentes et sommet nord) à l’ouest d’Andapa (haute Andramonta, bassin de la Lokoho: Nord-Est), forêt ombrophile sur gneiss et granite, [14°36’S, 49°23’E], 700 m, 10.XII.1950 - 3.I.1951, fr., et al. 24518 (K, MO, NY, P [2 sheets]). — Anjanaharibe (W du district d’Andapa), campement 2, [14°36’S, 49°23’E], 880 m, 12.XII.1950, fr., Service Forestier (Capuron) 913 (MO, P [2 sheets]). — District Andapa, Doany Anala, [14°28’S, 49°32’E], 24.VI.1951, fl., Service Forestier (Capuron) 3656 (P, TEF).

DESCRIPTION

Trees 8-25 m tall, dioecious; twigs glabrous. Leaves opposite, subcoriaceous, glabrous on both surfaces, 8-14 × 3.6-5.8 cm, obovate, base cuneate, apex usually shortly acuminate, rarely emarginate, midvein abaxially prominent, secondary venation camptodromous, 10 to 16 pairs, prominent, 1-2 cm from each other in median portion of blade, tertiary venation visible, more so abaxially. Petiole 2-6 mm long, glabrous, shallowly canaliculate above. Staminate flowers small, c. 2 cm long; pedicel c. 0.3-0.5 mm long; sepals 1 × 1 mm, widely ovate, imbricate, glabrous on both surfaces; petals 2-3 × 1.5 cm, ovate, imbricate, glabrous on both surfaces; stamens 5, filaments 1 mm long, broadened at the base, glabrous, anthers 1-1.5 mm long, oblong, glabrous; disk dish-shaped, 1 mm in diam., glabrous; ovary very reduced. Pistillate flower not seen. Infructescence a terminal, erect panicle, glabrous, 2.5-5 cm long; secondary axes borne at nearly 90° angles, held perpendicular to the primary axis, higher order axes zigzag in shape. Fruits drupaceous, mango-shaped, asymmetric, widely obovoid, 1.5-1.8 × 1.2-1.5 cm, markedly striate, green to dark green when fresh, yellow tan when dry.

REMARKS

Micronychia striata is known only from humid forest on granitic or gneissic substrate in the Anjanaharibe Sud Special Reserve W of Andapa and from the Anjanaharibe Nord massif near Doany (Fig. 2). Among the species with glabrous leaves, M. striata is distinctive in having opposite leaves and markedly striate fruits.

VERNACULAR NAME

Hoditrovy.

CONSERVATION STATUS

With an Extent of Occurrence <100 km ², an Area of Occupancy of 27 km ², and two subpopulations, only one of which occurs within a protected area (Anjanaharibe Sud Reserve), Micronychia striata is assigned a preliminary status of Endangered (EN B1ab(i,ii,iii)+2ab(i,ii,iii)) based on the IUCN Red List criteria (IUCN 2001).