Aerangis alcicornis (Rchb.f.) Garay, Bot. Mus. Leafl. 23: 157 (1972).
Homotypic Synonyms:
Angraecum alcicorne Rchb.f., Otia Bot. Hamburg.: 117 (1881).
Angorchis alcicornis (Rchb.f.) Kuntze, Revis. Gen. Pl. 2: 651 (1891).
Heterotypic Synonyms:
Aerangis calodictyon Summerh., Bull. Misc. Inform. Kew 1934: 214 (1934).
Aerangis lutambae Mansf., Notizbl. Bot. Gart. Berlin-Dahlem 12: 704 (1935).
Description:
Stem woody, up to 3 cm long, with numerous flexuous glabrous roots up to 2-3 mm diam. Leaves 2-8, linear-oblanceolate to elliptic-oblanceolate, apex usually acutely occasionally somewhat obtusely bilobed, the lobes unequal or subequal, up to 18 mm long, dark green, or greyish-green with a much darker distinct venation, 3-5-12 x 1-2.5 cm. Inflorescences arising below the leaves, horizontal or somewhat pendent, 10-30 cm long, bearing 3-15 flowers; peduncle up to 10 cm long, terete, bearing 3-6 tubular sheaths; rhachis straight; bracts shortly ovate, acute, 3-5 mm long. Flowers spreading, 8-17 mm apart, becoming closer together towards the tip of the inflorescence, white with pinkish tinges towards the tip of the spur; pedicel with ovary slender, 12-15 mm long, tinged pink. Dorsal sepal erect, oblong-elliptic, apiculate, 10-18 x 4-7 mm; lateral sepals similar, 10-18 x 5-6 mm. Petals elliptic, narrowed towards the base, 9-15 x 5-8 mm. Lip cuneate at the base, sub-orbicular to fan-shaped, rounded at the apex, sometimes with a short apiculus, 10-20 x 10-15 mm; spur filiform, somewhat incurved and slightly inflated towards the tip, 2-5-4 cm long. Column stout, 2-4 mm high, dilated below the anther; anther semi-globose, anther cap beaked; rostellum elongated, obtuse; pollinia ellipsoid; stipes dilated above, slender below; viscidium round or elliptic.
Habitat:
On trees, shrubs and lianes, in thicket; 200-1000 m.
Cultivation:
This is one of the species not in cultivation, although it must be an attractive one, with a broad lip not unlike the Madagascan Aerangis citrata. It seems likely Aerangis alcicornis would like fairly heavy shade and temperatures on the warm side of intermediate.
Note:
The type specimen was collected by John Kirk in 1859 while on David Livingstone's Zambezi expedition. La Croix and la Croix (1991) described how confusion arose over the collection locality. I do not propose to repeat that discussion here, except to say that some of the leaves on the type sheet, which must have given rise to the specific epithet alcicornis (like an elk's antlers), do not belong to that species but to Aerangis distincta, a species not described until 1987.
Distribution:
Rwanda to Mozambique
References:
La Croix, I. & Cribb, P.J. (1998). Orchidaceae (Part 2) Flora Zambesiaca 11(2) Page 382; La Croix, I. et al. (1983). Malawi Orchids Volume 1 Epiphytic Orchids National Fauna Preservation Society of Malawi Page 16; La Croix, I. et al. (1991). Orchids of Malawi A.A. Balkema, Rotterdam Page 245; 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. 16.01-2017; http://apps.kew.org/wcsp/
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