AFRICAN

ORCHIDS

Microcoelia macrorhynchia (Schltr.) Summerh. in J.Hutchinson & J.M.Dalziel, Fl. W. Trop. Afr. 2: 454 (1936).
Homotypic Synonyms:
Angraecum macrorhynchium Schltr., Bot. Jahrb. Syst. 38: 22 (1905).
Gussonea macrorhynchia (Schltr.) Schltr., Beih. Bot. Centralbl. 36(2): 93 (1918).
Encheiridion macrorhynchium (Schltr.) Summerh., Bot. Mus. Leafl. 11: 162 (1943).
Heterotypic Synonyms:
Angraecum marcrorrhynchium Schltr., Westafr. Kautschuk-Exped.: 284 (1900), nom. inval.
Description:
Epiphytic plant. Stem often small, up to 15 (-29) x 1.5-3 (-5) mm. Scale-leaves acute to acuminate, with 5-7 nerves, up to 4.0 (-7.1) mm long. Roots generally few, variously spreading, ± undulating, distal ends mostly free, with few branches or not, ± appressed to the substrate, terete to ± flattened, smooth, up to 70 mm x 1.0-3.0 mm. Inflorescence(s) ± erect to pendulous, up to 10 (-17) cm long, up to 5 (-14) simultaneously, usually ± dense, each with up to 18 (-25) flowers; peduncle short, up to 10 mm long, greenish; rachis straight or indistinctly flexuose, terete, ± flattened at the flower joints, greenish; bracts sheathing, acute, basally 3-nerved, api-cally indistinctly 1-nerved, 0.7-1.9 mm long, brownish. Pedicel short, ± straight to distinctly twisted, up to 3.2 mm long, pale brownish green; ovary slightly curved, faintly furrowed, 1.0-1.9 xO.4-0.7 mm, pale brownish green. Flowers ± horizontal, up to 11.5 mm long including ovary and pedicel, dorsal sepal pale brown; lateral sepals white with brownish mid-nerve; petals white; lip white with a yellowish green spot at the base; spur pale brown to orange-beige apically; anther greenish brown. Glandular hairs very sparse, occasionally seen at the base of the dorsal sepal. Dorsal sepal distinctly hood shaped, ovate, acute, apex ± recurved or not, 3-nerved, (2.0-) 3.0-4.9 (-6.0) x 1.0-2.0 (-4.3) mm. Lateral sepals asymmetric, ovate, acute, apex ± recurved, 3-nerved, 3.2-5.7 x 1.5-2.4 mm. Petals asymmetric, ovate, obtuse to subacute, ± erose, 1-nerved with side branches, 3.0^4.5 (-5.5) x 1.6-3.4 mm. Labellum 3-lobed; mid-lobe spathulate, ± semicircular in outline, distinctly dentate with minutely erose margins, apically folded and distinctly decurved, giving an emarginate appearance, 5-nerved, lateral nerves branched; side-lobes erect, oblong, succeeded on each inner side of a distinct plate-like thickening, wedge-shaped and ± closing the spur mouth, 4.5-6.0 (-7.3)x3.6-5.8 mm, mid-lobe alone up to 5.5 mm; spur long, pendulous, ± straight, in early anthesis distinctly incurved, at late anthesis tapering apically into a distinct ± conical inflation, (3.9-) 5.0-6.5 mm long, along curve up to II .0 mm. Column short, ± distinctly recurved, truncate (0.7-) 1.0-2.0 mm long, (0.5-) 1.0-1.7 mm high; androclinium shallowly excavated, ± horizontal; rostellum lobes very long, acute, inserted just below androclinium, bifid from the outermost 1/3-1/4 of the total length, ± porrect in anthesis, in early anthesis pointing into spur mouth, (2.8-) 3.9-4.7 (-5.0) mm long, at the base each lobe is up to 0.35 mm wide. Anther hemispherical in side view, bivalvate dorsally; in back view ± triangular, tapering into a straight, relatively short, acute or subapiculate apex, margin ± irregular, 1.0-2.2 x 0.7-1.6 mm. Pollinia asymmetric; in side view ± orbicular, 550-730 x 470 -690 µm in median section obo vate, 310-530 µm thick. Stipes long, ligulate, ± straight; apical part with a distinct ± massive, obconical, head-like apex, channelled; basal part connate with the viscidium to its apex, distinctly grooved, 4.2-4.8 mm long (total length up to 5.5 mm); viscidium ± ensiform, posterior end truncate, 1.4-2.2 x 0.2-0.3 mm. Capsule long, sometimes short, ± narrowly ellipsoid, slightly curved or not, apex ± distinctly bent, (9-) 15-24 x (2.5-) 3.5-4.0 mm; pedicel short, ± straight, up to 5.0 mm long. Seeds ± cylindrical, bottleshaped to fusiform, testa cells narrowly elongate (in a dry state), with club-shaped to distinctly hook-shaped processes; anticlinal walls ± sulcate with indistinct or distinct striations, terminal ends slightly protruding (230-) 320-410 (-440) x 40-70 mm.
Habitat:
Rain forest and riverine forest extending to dense woodland. Often found in secondary forest and plantations. Epiphytic, usually on smaller branches and twigs in ± exposed positions. Occasionally found in association with Solenangis clavata (Rolfe) Schltr. Altitude. 200-1100 m.
Flowering period:
Recorded from both rainy seasons, with a tendency of concentration to the earlier parts.
Cultivation:
As given for the genus, cool growing epiphyte.
Distribution:
Trop. Africa
References:
Flora of Tropical East Africa Part 3 Cribb 1989; Flora Zambesiaca Vol 11 Part 2 Pope 1998; WCSP (2017). 'World Checklist of Selected Plant Families. 03.03-2017; http://apps.kew.org/wcsp/
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