AFRICAN

ORCHIDS

Microcoelia smithii (Rolfe) Summerh., Bot. Mus. Leafl. 11: 148 (1943).
Homotypic Synonyms:
Angraecum smithii Rolfe, Bull. Misc. Inform. Kew 1895: 37 (1895).
Gussonea smithii (Rolfe) Schltr., Beih. Bot. Centralbl. 36(2): 94 (1918).
Description:
A dwarfish epiphytic plant. Stem short, (2-)3-9 (—18)x 1—2 mm. Scale-leaves ± rostrate, up to 2 mm long, with c. 3 nerves. Roots few, ± radially spreading, usually closely attached to the substrate, ± densely crowded, unbranched, ± terete, smooth, up to 15 cm x 1-1,5 mm. Inflorescence(s) ± erect spreading, up to 50 mm long, up to 7—12(—18) simultaneously, usually dense, each with up to 12 flowers; peduncle short, up to 15 mm long; rachis ± flexuose, terete, smooth; bracts ± loosely sheathing, acute to subacute, with 3 nerves, up to 1.6 mm long. Pedicel minute, up to 0.5 mm long; ovary ± straight, dis-tally furrowed, (0.8-)1.3-2.2 x (0.3-)0.5-0.7 mm. Flowers horizontal to ± erect, up to 4.5 mm long including ovary and pedicel; tepals white; spur whitish with ± greenish apex. Glandular hairs very sparse, mainly scattered on rachis, base of bracts, pedicel and ovary, basal parts of the perianth. Perianth ± similar, narrowly ovate to ovate, acute to subacute, distinctly thickened along the central nerve. Dorsal sepal (1.2—)2.0—2.7 (-3.0) x (0.4-)0.7-0.9 mm. Lateral sepals slightly asymmetric, (1.3—)2.3—2.7 (-3.2) x (0.4-) 0.6-0.8 mm. Petals slightly asymmetric, thin, (1.0-)2.0-2.6 x (0.4—)0.6-0.8 mm. Labellum ± navicular; mid-lobe narrowly ovate, acute, ± folded, with 3 nerves; side-lobes small, ± oblong, (1.2-)2.3-2.8 x 0.6-0.9 mm; spur ± perpendicular to slightly decurved, conical to cylindrical, obtuse (1.0—) 1.6—2.2 mm long and 0.3-0.4 mm at the apex. Column short, truncate, outer sides ± concave, (0.2-)0.4-0.6 mm long, (0.3-)0.5-0.7 mm high; androclinium shallowly excavated, with a small hump in the centre, rostellum lobes ± incumbent to perpendicular, ± rectangular, up to 0.2 mm long. Anther ± bivalved, hemispherical in side view, tapering into a truncate short and thin rim, ± rounded-apiculate at the very apex, 0.5-0.7 x 0.5-0.6 mm. Pollinia asymmetric; in side view ± elliptical, (190—)250—310 x (150—) 190—220 /µm; in median section slightly compressed, ± elliptic, 140-160 pm thick. Stipes spathulate apically, sigmoid 270-390 pm long, 80—110(—140) µm wide at the apex; viscidium ± rectangular, posterior end rounded, 220-270 x 110-140 pm, transparent. Capsule ± oblong, 3.5-4.0 x c. 2 mm; pedicel short, up to 0.5 mm long. Seeds ± cylindrical to fusiform or ± bottle-shaped; testa cells narrowly elongate (in a dry state), processes club-shaped and more sparsely hook-shaped; anticlinal walls furrowed, (315-1350-410 (—430) x (23—) 30-60 µm (40 dry seeds measured).
Habitat:
Dry deciduous forest, altitude range c. 600 m.
Flowering period:
Mainly during the dry season.
Notes:
Evidently allied to icrocoelia globulosa (Hochst.) L.Jonss.. of which it may prove to be a local race or variety. It may be distinguished by its smaller size, more slender inflorescences, smaller flowers and narrow perianth members including the lip. In general floral structure there is close agreement between the two species.
Cultivation:
As given for the genus, hot to warm growing epiphyte.
Distribution:
Kenya to Malawi
References:
Orchids of East Africa Piers 1968; A Monograph of the Genus Microcoelia [Orchidaceae] Jonsson 1981; Flora of Tropical East Africa Orchidaceae Part 3 Cribb 1989; Orchids of Kenya Stewart 1996; African Orchids in the wild and Cultivation La Croix 1997; Flora Zambesiaca Vol 11 Part 2 Pope 1998; AOS Bulletin Vol 72 No 3 2003; Angraecoid Orchids Stewart, Hermans and Campbell 2006; WCSP (2017). 'World Checklist of Selected Plant Families. 03.03-2017; http://apps.kew.org/wcsp/
Images:
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Habitat/In situ Habitat/In situ Habitat/In situ
microcoelia smithii microcoelia smithii close microcoelia smithii in situ
Photograph©Backmann. Swiss Orchid Foundation at the Herbarium Jany Renz Image used with kind permission. Photograph©Backmann. Swiss Orchid Foundation at the Herbarium Jany Renz Image used with kind permission. Photograph©Backmann. Swiss Orchid Foundation at the Herbarium Jany Renz Image used with kind permission.