Aerangis collum-cygni Summerh. in Bull. Misc. Inform., Kew 1927: 418 (1927).
Heterotypic Synonyms:
Aerangis compta Summerh., Bull. Jard. Bot. État 25: 259 (1955).
Description:
Epiphytic herb; stem woody, to 10 cm long; roots numerous, 2–4 mm in diameter. Leaves 4–7, distichous, 6–17 × 1.5–5.5 cm, obliquely oblanceolate, unequally 2-lobed at apex with the lobes rounded or subacute; lamina fleshy, dark green dotted with black. Inflorescences erect, spreading or pendent, 4–16-flowered.Peduncle 4–8 cm long with 2–3 tight sheaths; rhachis zigzag. Pedicel and ovary 2–3.5 cm long; bracts 3–5 mm long, spreading, triangular. Flowers white, usually tinged with pink at the tips of the tepals; spur pale greenish-brown. Dorsal sepal erect or slightly reflexed, 13–15 × 3.5–5 mm, lanceolate, acute or acuminate; lateral sepals reflexed, 13.5–17 × 2.5–4 mm, narrowly lanceolate, acuminate, slightly winged on the back. Petals reflexed, 9–15 × 2.5–4 mm, lanceolate, acuminate or cuspidate, 9–15 × 2.5–4 mm. Lip deflexed, 10–14.5 × 3.5–6 mm, lanceolate but with lateral margins strongly recurved; spur pendent, 6–7.5 cm long, straight or incurved, gradually tapering. Column 6–8 mm long, with a short, pointed tooth projecting into the mouth of the spur; anther cap hemispherical wth a short, central beak. Capsules cylindrical, 6 cm (2 in.) long, 4 mm in diameter.
Habitat:
Moist woodland, rainforest and in old plantations 800–1200 m.
Notes:
This species can be distinguished from two western species of similar size quite easily. It has smaller flowers with a longer spur and column than A. biloba, and slightly smaller flowers with broader tepals and a longer column than A. arachnopus. It also has smaller flowers than the Kenyan species A. confusa. It seems to be closely related to A. jacksonii, which occurs in some of the same forests in Uganda, but the flowers have a longer column and the leaves are much wider and closer together than in that species.
Cultivation:
Read more of Cultivation of Aerangis collum-cygni Summerh.
Distribution:
Zambia, Cameroon; Central African Republic; Tanzania; Uganda; Zaire.
References:
Hillerman, F. and A. Holst. 1986. An introduction to the cultivated Angraecoid orchids of Madagascar. Timber Press, Portland, Ore; African orchids in the wild and in cultivation. Timber Press, Portland, OR. Stewart, J., J. Hermans, and B. Campbell. 2006, Angraecoid Orchids. Timber Press, Portland, Stewart, J. (1979). Stewart, J. (1979). A Revision of the African Species of Aerangis (Orchidaceae) Kew Bulletin, Vol. 34, No. 2 (1979), pp. 239-319. WCSP (2017). 'World Checklist of Selected Plant Families. 18.01-2017; http://apps.kew.org/wcsp/
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