AFRICAN

ORCHIDS

Satyrium riparium Rchb.f., Flora 48: 183 (1865).
Description:
A terrestrial herb 3.-5-7.5 dm. high, the aerial parts almost entirely glabrous ; tubers ellipsoid to elongate ovoid, 1-3.5 cm. long, 8-14 mm. in diameter, ± tomentose; roots slender, flexuous, pubescent. Sterile stem short, 3-4-leaved; 1-2 lower leaves sheath-like, obtuse, the upper 2 leaves spreading, lanceolate to elliptical, acute, up to 4-11 cm. long and 2-3.5 cm. broad. Fertile stem erect, slender to stout, nearly covered by sheathing leaves; sheaths 9-12, lanceolate, acute, up to 4-7 cm. long and 1-3 cm. broad, the upper ones smaller, resembling the bracts. Inflorescence ± cylindrical, 11-28 cm. long, 2.5-3 cm. in diameter, usually rather loosely many-flowered; bracts reflexed, lanceolate, acute, 1-3 cm. long. Flowers sessile, curved outwards, green or yellow-green, turning brown or purplish; ovary purple or red, 7-9 mm. long, densely long-papillose. Sepals and petals decurved, united to one another and to the lip in their lower half; intermediate sepal elliptical-oblong, rounded; laterals obliquely oblong-elliptical, obtuse; all 5-7 mm. long. Petals a little shorter than the sepals, oblanceolate, rounded, shortly pubescent and ciliolate. Lip obliquely ellipsoid, hooded, the apex shortly recurved, 5.5-7 mm. long, fleshy; spurs straggling, very slender, 1.7-2.4 cm. long, sometimes with an additional much shorter pair. Column curved, 5 mm. high; stigma erect, transversely elliptical, 1.5 mm. high, rostellum porrect, 3-lobed, the side lobes short, triangular, the middle lobe much longer, broadly spade-shaped from a narrow base.
Habitat:
Montane grasslands, swampy grasslands, dambo. Alt. 1100-2100 m.
Flowering time:
October-January.
Notes:
Satyrium riparium appears to be allied to Satyrium volkensii Schltr. In the former the ovary is densely papillose and the lip is 4.5-7 mm long. In the latter species the ovary is glabrous and the lip is 4-5.5 mm long.
Cultivation:
As given for the genus.
Distribution:
The Democratic Republic of Congo (Zaire), Tanzania, Angola, Zambia, Malawi, Zimbabwe.
References:
Orchidaceae of West-central Africa, vol. 1, Gdansk University Press Gdansk 2010, La Croix, I. et al. (1991). Orchids of Malawi A.A. Balkema, Rotterdam; La Croix, I. & Cribb, P.J. (1995). Orchidaceae (Part 1) Flora Zambesiaca 11(1); Flora of Tropical East Africa Summerhayes Orchidaceae Part 1 1968; Flora of Tropical Africa, Vol 7, page 12, (1898) Author: (By R. A. Rolfe.)
Images:
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Habitat/In situ 
Satyrium riparium 01 
Photograph© Warren
McCleland. Image used
with kind permission.