Monographs Details: Macrocentrum angustifolium Gleason
Authority: Maguire, Bassett, et al. 1953. The Botany of the Guayana Highland. Mem. New York Bot. Gard. 8 (2): 87-160.
Family:Melastomataceae
Description:Latin Diagnosis - Frutex humilis; folia isomorpha, anguste elliptica, incurvo-denticulata, glabra; flores 5-meri, breviter pedicellati in axillis foliorum superiorum, ad basim a jugo foliorum parvorum bracteati; stamina isomorpha; antherae lineares; connectivum basi in calcar retrorsum breve productum.

Species Description - Widely branched half-shrub up to 3 dm. tall, the spreading branches very numerous; internodes 4-7 mm. long, glabrous, with 2 shallow lateral furrows. Leaves isomorphic, linear-elliptic to linear-oblanceolate, up to 18 mm. long and 3 mm. wide, acute, tapering to a sessile petiole-like base, entire below, irregularly dentate in the distal half or two-thirds with a few small incurved teeth, glabrous, 1-nerved or with very faint indication of a pair of lateral nerves; secondaries obsolete. Flowers 5-merous, solitary at the end of short (3 mm.) minutely scabrellate peduncles; each peduncle solitary and terminal but apparently axillary, subtended at its very base by a pair of reduced leaves, the stem proliferating from the axil of one of the adjacent foliage-leaves. Kypanthium cup-shaped, thin-walled, about 2.5 mm. long, rather obviously 10-nerved, scabrellate opposite the torus. Calyx-tube prolonged 0.4 mm.; sepals 4.8 mm. long from the torus, from a triangular base, soon narrowed to a subulate tip. Petals "white to pink," ovate, about 6.5 mm. long. Stamens isomorphic but slightly unequal; filaments flat, glabrous; anthers linear, about 3 mm. long, prolonged at base into a terete connective 0.5 mm. long and below the summit of the filament into a straight, retrorse, subulate, dorsal spur 0.5 or 1 mm. long. Ovary superior, subglobose, tipped with 5 erect fleshy lobes; style slender; stigma punctiform.

Discussion:

TYPE: on wet rocks along Savanna Creek, summit of Cerro Sipapo, Bassett Maguire & Louis Politi 27540; New York Botanical Garden. Paratype: 28223 is identical: it is described as a perennial subshrub 2-4 dm. tall, leaves shining green, flowers pink, stamens pale yellow, along stream, Cano Profundo, North Branch, summit of Cerro Sipapo.