AFRICAN

ORCHIDS

Polystachya supfiana Schltr., Bot. Jahrb. Syst. 38: 9 (1905).
Description:
An epiphytic herb, 9-26 cm high, glabrous except for the lip; Pseudobulbs tightly clustered, narrowly cylindrical, from a short creeping rhizome, 3-19 cm long, 1-1.5 mm wide, clothed in 2-3 membranous basal cataphylls. Leaf linear to obovate-lanceolate, coriaceous, base cuneate, acute to obtuse, 5.3-17 cm x 6-5-11 mm, articulated I mm above the apex of the pseudobulb. Inflorescence shorter than the leaf, a simple raceme, 0-8-3-2 cm long, bearing up to 4 flowers successively; peduncle stout, to 1.4 cm long, with a membranous basal sheath; bracts triangular, amplexicaul, 1-4 mm long, apiculate to aristate. Flowers yellow, ± purple, striped green. Dorsal sepal triangular-ovate, 4-8-5 x 4 mm, shortly apiculate, 1-3-nerved; lateral sepals obliquely triangular-oblong, 9-5-14 x 5-8 mm, 1-3-nerved; mentum ovoid conical, 5-7-5 mm long. Petals narrowly spathulate to linear, apex acute, 3-6-5 x 0.5-1.5 mm, 1-3-nerved. Lip strongly recurved in the lower third, unguiculate, distinctly trilobed in the lower to upper third, 9-12 x 3 8-6 mm; claw glandular-pubescent; mid-lobe obovate-quadrate, 2.7-6.5 x 3- 5 mm, shortly apiculate; lateral lobes porrect, broadly triangular, not exceeding the length of the mid-lobe; callus in the middle to the lower third. Column semi-terete, 1 mm high, column foot 8-13 mm long; pollinia ovoid globose.
Habitat:
Epiphyte in submontane forest, some specimens observed on trunks of Harungana mada-gascarensis Lam. ex Po. Altitude 0-1250 m.
Cultivation:
As given for the genus, hot to cool growing epiphyte.
Notes:
The type of Polystachya supfiana deposited at B by Schlechter was destroyed and the only remaining type material is a tracing of a drawing the type specimen deposited at K (lectotype), a copy of a drawing published by Schlechter (1905,1932) and a diagnosis deposited at BR. Additionally, there is a drawing of a lip with its dimensions in the K specimen made by Summerhayes in 1934, when the type has yet existed. Polystachya letouzeyana and Polystachya kubalae are usually sunk under Polystachya supfiana, however both are easily distinguishable from the latter species by glabrous flowers and length of the pseudobulbs. Pseudobulbs of Polystachya supfiana are up to 3.5 cm long whereas those of Polystachya letouzeyana are 3.5-7.5 cm long and up to 19 cm long in Polystachya kubalae. Generally Polystachya supfiana is a small plant with short pseudobulbs, short inflorescence and pubescent flowers.
Distribution:
S. Nigeria to Gabon
References:
Orchidaceae of West Central Africa Vol. 2 Szlatch. etal 2014; A Monograph of the subtribe Polystachyinae Schltr. (Orchidaceae) by Joanna Mytnik-Ejsmont, University of Gdansk 2011; World Checklist of Monocotyledons. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the Internet; http://www.kew.org/wcsp/monocots/ accessed 12.04.2017
Images:
Click on each image to see a larger version.