Ypsilopus erectus (P.J.Cribb) P.J.Cribb & J.Stewart, Kew Bull. 40: 417 (1985).
Ypsilopus longifolius var. erectus P.J.Cribb, Kew Bull. 32: 177 (1977).
Epiphytic herb.Stem short, to c. 6 cm long, usually shorter, covered with acutely pointed old leaf bases.Roots c. 4 mm in diameter, smooth, grey. Leaves 4–5, forming a fan; blades 3–15 cm × 3.5–6 mm, linear, conduplicate, somewhat recurved.Inflorescences 1–2, arising at base of plant, suberect or arching, 5–20 cm long, fairly laxly 4–12-flowered.Flowers white, the spur greenish at tip, the pedicel and ovary sometimes salmon-pink. Pedicel and ovary slender, 15 mm long; bracts 1.5–2 mm long, scarious.Sepals 5–8 × 2.5–3 mm, lanceolate, acute, the margins rolled back so that they appear narrower; dorsal sepal erect, lateral sepals deflexed.Petals 5–7 × 1.5–2 mm, lanceolate, acuminate, reflexed.Lip more or less entire to obscurely three-lobed, 5–7 × 2.3–3 mm, rhomboid, acute; spur 3.5–6 cm long, very slender, gently incurved.Column 1.5–2 mm long, anther cap brown.
Specimens occurring at lower altitudes are more robust than those from higher up. A possible hybrid has been found in Malawi between this species and Tridactyle tricuspis. The plant grew with the putative parents on the same branch, and was intermediate in appearance between them, the flowers being pure white with a 3-lobed lip and a spur 3 cm long.
Mountainside miombo and mixed deciduous woodland on slopes, also in montane forest where it has been recorded as epiphytic in cedar 1000–1800 m.
As given for the genus, warm to cold growing epiphyte or lithophyte.
Tanzania to Cape Prov.
Orchids of East Africa Piers 1968; Wild Orchids of Southern Africa Stewart, Linder, Schelpe & Hall 1982; Flora of Tropical East Africa Orchidaceae Part 3 Cribb 1989; African Orchids in the Wild and Cultivation La Croix 1997; Flora Zambesiaca Vol 11 Part 2 Pope 1998; Angraecoid Orchids Stewart, Hermans and Campbell 2006; WCSP (2017). 'World Checklist of Selected Plant Families. 15.03.2017; http://apps.kew.org/wcsp/
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|Photograph©Bart Wursten. Image used with kind permission.||Photograph©Bart Wursten. Image used with kind permission.||Photograph©Bart Wursten. Image used with kind permission.|