Satyrium volkensii Schltr., Bot. Jahrb. Syst. 24: 425 (1897).
Satyrium trachypetalum Kraenzl., Bot. Jahrb. Syst. 24: 505 (1898).
Satyrium leptopetalum Kraenzl., Bot. Jahrb. Syst. 36: 119 (1905).
Satyrium dizygoceras Summerh., Bull. Misc. Inform. Kew 1932: 508 (1932).
A terrestrial herb 2-11 dm. high, mostly glabrous; tubers globose to fusiform-cylindrical, 1-4.5 cm. long, 7-22 mm. in diameter, ± tomentose; roots slender, flexuous, pubescent. Sterile stem to 5 cm. long, 3-4-leaved; lower 1-2 leaves short, sheath-like, obtuse, the upper 1-3 lanceolate to oblong-elliptical, acute, up to 5-13 cm. long and 2-6 cm. broad. Fertile stem erect, slender to stout, covered by sheathing leaves; sheaths 8-13(-15), lanceolate, acute, up to 2.5-11 cm. long and 1-3 cm. broad. Inflorescence narrowly cylindrical, (5-)10-42 cm. long, 1.5-2.5 cm. in diameter, loosely to densely many-flowered; bracts reflexed, lanceolate, acute, 1-2.5 cm. long. Flowers curved outwards, sessile, green to yellow-green, sometimes tinged purplish or brownish; ovary 5-10 mm. long. Sepals and petals decurved, united to one another and to the lip in their lower third or half; intermediate sepal oblanceolate, rounded, 3.5-5.5 mm. long, scarcely I mm. broad; laterals much twisted, obliquely and curved elliptical-oblong, obtuse, 4-6.5 mm. long, ± 1.5 mm. broad. Petals oblanceolate, rounded, 3-4.-5 mm. long, 0.5 mm. broad, pubescent and ciliolate. Lip ellipsoid, much hooded, the apex shortly recurved, 4-5.5 mm. long; spurs rather straggling, very slender, 11-23 mm. long, 2 very short additional spurs often present. Column inside lip, much curved, 3-5 mm. high; stigma orbicular or broader than high, 1-2 mm. high, rostellum deflexed, 3-lobed, 1.5 mm. long, the side lobes small, triangular, the middle lobe much longer, broadly spoon-shaped from a narrow base.
Brachystegia and mixed woodland, grassland with scattered bushes, montane grassland and dambo margins Alt.1200–2400 m.
As given for the genus.
Nigeria, Cameroon, the Democratic Republic of Congo (Zaire), Kenya, Tanzania, Zambia, Malawi, Zimbabwe.
Orchidaceae of West-central Africa, vol. 1, Gdansk University Press Gdansk 2010; Flora of Tropical East Africa Summerhayes Orchidaceae Part 1 1968
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