AFRICAN

ORCHIDS

Microcoelia physophora (Rchb.f.) Summerh., Bot. Mus. Leafl. 11: 148 (1943).
Homotypic Synonyms:
Angraecum physophorum Rchb.f., Otia Bot. Hamburg.: 77 (1881).
Gussonea physophora (Rchb.f.) Ridl., J. Linn. Soc., Bot. 21: 492 (1885).
Angorchis physophora (Rchb.f.) Kuntze, Revis. Gen. Pl. 2: 651 (1891).
Epidorchis physophora (Rchb.f.) Kuntze, Revis. Gen. Pl. 2: 660 (1891).
Mystacidium physophorum (Rchb.f.) T.Durand & Schinz, Consp. Fl. Afric. 5: 54 (1894).
Description:
Stem short or ± long, (8-) 15-20 (-50) x 2-3(-4) mm. Scale-leaves rostrate, up to 5 mm long, with c. 5 nerves. Roots few to many, ± radially spreading, ± densely crowded, mostly characteristically attached to the substrate, forminga ± conical tuft, mostly unbranched, ± flattened to rounded triangular in transverse section or ± terete at the apical free parts, irregularly undulating, ± smooth when wet, ± uneven when dry, pneumathodes clearly visible as whitish linear spots in both conditions, up to 35 cm X (1.5—)3(—5) mm. Inflorescence(s) short, ± erect-spreading, up to (10—)25(—50) mm long, up to 6(—15) simultaneously, usually dense, with up to 15 flowers, ± concentrated at the apex of rachis; peduncle distinct, up to 9(— 13) mm long: rachis ± straight to indistinctly flexuose, ± angular, smooth; bracts distinctly sheathing, acute or subacute, 1-nerved, up to 2 mm long. Pedicel long, ± straight, slightly furrowed, 5-9(-13) mm long, whitish; ovary ± straight to slightly curved, furrowed, lobes obtusely keeled. 2.3-4.8 x 0.5-1.3 mm, pale brownish. Flowers ± erect-spreading, up to 8 mm long including ovary; tepals whitish with a greenish central band on the sepals; labellum with a whitish mid-lobe, side-lobes greenish, anther and column greenich. Glandular hairs very sparse, mainly distributed on peduncle and rachis, base of bracts, pedicel and ovary, basal parts of the perianth to the apex of the spur. Dorsal sepal hooded, ovate, ± acute, with 3 nerves, slightly thickened along the central nerve, 1.7-2.6 x 1.0-1.7 mm. Lateral sepals asymmetric, slightly convex, ovate, acute, subapiculate, with 3 nerves, slightly thickened along the central nerve, connate below ovary, 2.2-3.1 x 1.6-2.2 mm. Petals ovate, obtuse, 1-nerved, 1.4—2.5x0.7-1.1 mm. Labellum 3-lobed; mid-lobe tongue-shaped, ± obtuse, with 3 nerves; side-lobes indistinct, rounded, fleshy, extended over spur mouth closing it considerably, 1.1-2.7 (—3.1) x 0.4—1.1 mm, mid-lobe alone up to 0.7-2.0 x 0.4— 1.0 mm; spur perpendicular or occasionally apically curved towards ovary, cylindrical, tapering into a distinct ± inflated, obtuse apex, 7.5-9.5(-l 1.0) mm long, apical inflation up to 1.8 mm in diameter (side view). Column short, 0.7-1.1 mm long and high, greenish; androclinium distinctly excavated, midridge ± prominent; rostellum lobes ± porrect, concave, ± wedge-shaped, smooth, up to 0.6 mm long; stigmatic area rounded-oblong. Anther hemispherical in side view, with a short ± recurved beak-shaped apex, 0.8-1.0 mm long and wide, greenish. Pollinia asymmetric; in side view ± obovate to elliptic, (420-)440-540 (-580) x (250-)280-400(-440) pm: in median section ± obovate, up to 310 µm thick. Stipes ligulate, spathulate apically, sigmoid, 470-750(-940) pm long, 130—200(—250) µm wide at the apex; viscidium broadly elliptic to rounded-oblong, distinctly notched at both ends, ± convex, membranous, (300-)360-500 x 300-340 µm. Capsule cylindrical to narrowly ellipsoid. 10-16 x 4—5 mm; pedicel distinct, up to 13 mm long. Seeds bottle-shaped to ± cylindrical, occasionally ± fusiform, testa cells narrowly elongate (in a dry state), with small club-shaped or loop-shaped processes; anticlinal walls smooth to ± sulcate, indistinctly striated or not, terminal ends only indistinctly elongated, (210-)300-375 x 50-80 µ.
Habitat:
Coastal bushland-woodland extending up in woodland, epiphytic in exposed to more or less shaded conditions, often firmly attached on larger branches. Altitude. 0-500 m.
Flowering period:
From the latter part of the dry season to the early rainy season.
Cultivation:
As given for the genus, hot growing epiphyte.
Notes:
This species, which has not previously been recorded from Africa proper, can be recognised by the rather flattened roots, the long spur thickened at the apex and the narrow ligulate (Meet and concave lip lamina. The mouth of the spur is much narrowed by the infolding of the edges on either side. The androelinium slopes upwards somewhat but the porrect rostellum is comparatively short. The two pyriform pollinia are attached, by a stipes of moderate length and somewhat widened above, to a large heart-shaped viscidium.
Distribution:
SE. Kenya to E. Tanzania (incl. Zanzibar), N. & NW. Madagascar
References:
Flora Of Madagascar Perrier 1939; Encyclopedia of Cultivated Orchids Hawkes 1965; A Monograph of the Genus Microcoelia [Orchidaceae] Jonsson 1981; Orchids of Madagascar Hermans 2007; Field Guide to the Orchids of Madagascar Cribb & Herman 2009 WCSP (2017). 'World Checklist of Selected Plant Families. 03.03-2017; http://apps.kew.org/wcsp/
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Photograph ©Gilles Grunenwald. Image used with kind permission. Photograph ©Gilles Grunenwald. Image used with kind permission. Photograph ©Gilles Grunenwald. Image used with kind permission. Photograph ©Gilles Grunenwald. Image used with kind permission. Photograph ©Gilles Grunenwald. Image used with kind permission. Photograph ©Gilles Grunenwald. Image used with kind permission.