AFRICAN

ORCHIDS

Microcoelia decaryana L.Jonss., Symb. Bot. Upsal. 23: 95 (1981).
Description:
Epiphytic plant. Stem short, up to 15 x 2-3 mm. Scale-leaves acute to ± obtuse, with 4-5 nerves, up to 2 mm long. Roots few to many, variously spreading, ± twisting and much branched distally, terete to obtusely triangular in transverse section where adnate to the substrate, smooth, up to 20 cm x (0.5—) 1.5—2.5(—3.0) mm. Inflorescence(s) erect, spreading, up to 50 mm long, up to 17 simultaneously, dense, each with up to 23 flowers; peduncle short, up to 5 mm long; rachis ± straight, terete, slightly angled at the joint of the flower; bracts sheathing, acute, distinctly 1-nerved, up to 1.6 mm long. Pedicel short, furrowed, up to 1.5 mm long; ovary ± straight, valves ± sharply keeled, up to 2.5 mm long. Flowers ± horizontal, up to 7 mm long including ovary and pedicel, whitish tinged with green. Glandular hairs sparsely scattered on rachis, pedicel, ovary and at the basal part of the sepals and spur. Dorsal sepal hooded, elliptic, acute, with 1 nerve, c. 2 x 0.8 mm. Lateral sepals curved, elliptic, acute, with 1 distinctly thickened nerve, c. 2.5x1.5 mm. Petals slightly asymmetric, elliptic, acute, subapiculate, with I nerve, c. 2x1 mm. Labellum large, 3-lobed; mid-lobe cup-shaped, broadly obovate, with 5 nerves, lateral nerves branched; side-lobes rounded, with a distinct ridge-like thickening at each side of spur mouth, c. 3 x 2.5 mm, mid-lobe along up to 2.1 mm long; spur ± appressed to ovary, cylindric, from the narrow mouth ± gradually inflated towards the obtuse apex, c. 4 mm long, apical inflation up to 0.6 mm in diameter. Column short, truncate, slightly recurved, 0.4 mm long, 0.9 mm high; androclinium shallowly excavated, with an indistinct midridge; rostellum lobes ± horizontal, rectangular, sides ± angled and turned down, up to 0.4 mm long. Anther ± bivalved, hemispherical, tapering into a ± rectangular prolongation, up to 1.0x0.7 mm. Pollinia minute, ± globose, asymmetric, with a minute protrusion centrally; in side view up to 300 x 280 µm, in median section up to 280 µm thick. Stipes narrowly cuneate; in side view slightly sigmoid, up to 780 µm long, c. 110 pm wide at the base; viscidium minute, saddleshaped, apex rounded-triangular and connate with stipes, c. 330 µm long and wide.
Habitat:
Dry bushland—woodland, altitude, c. 300 m.
Flowering period:
Recorded from the beginning of the rainy season.
Cultivation:
As given for the genus.
Distribution:
W. Madagascar
References:
WCSP (2017). 'World Checklist of Selected Plant Families. 03.03-2017; http://apps.kew.org/wcsp/
Images:
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