AFRICAN

ORCHIDS

Listrostachys pertusa (Lindl.) Rchb.f., Bot. Zeitung (Berlin) 10: 930 (1852).
Homotypic Synonyms:
Angraecum pertusum Lindl., Companion Bot. Mag. 2: 205 (1837).
Angorchis pertusa (Lindl.) Kuntze, Revis. Gen. Pl. 2: 651 (1891).
Heterotypic Synonyms:
Listrostachys jenischiana Rchb.f., Bot. Zeitung (Berlin) 10: 930 (1852).
Listrostachys behnickiana Kraenzl., Notizbl. Königl. Bot. Gart. Berlin 5: 122 (1909).
Description:
A robust epiphyte; on old plants, woody stem to 15 cm, long; roots 2-3 mm in diameter, with golden-brown growing tips. Leaves 9 to 15, distichous, set close together, 10-35 x 1-2 cm, linear, folded, very stiff- textured, almost equally and obtusely bilobed at the apex. Inflorescences arising from the axils of lower leaves, 30 cm long, densely many-flowered, the flowers arranged in two rows. Flowers white, with a green spot at the opening of the spur, sometimes spotted with red. Peduncle 5 cm long. Pedicel and ovary 1.5 mm long, papillose; bracts very short. Sepals 3 x 1.5 mm, ovate; petals slightly smaller. Lip 7-8 mm long, the mouth of the spur 3 mm from the base, the apical part 4 x 3 mm, rectangular, the apex with a suggestion of three teeth. Spur green or sometimes reddish, 4 mm long, the apical half swollen to 1.5 mm wide, the apex rounded. Column 1-2 mm long.
Habitat:
Evergreen forest, 500-600 m.
Cultivation:
This is a very obliging plant, growing well either mounted or in a pot, and flowering regularly in summer (June). You can grow it in intermediate temperatures (although it should also do well in warm), in moderate shade.
Notes:
Although the flowers are small, chef all open together and the effect is attractive and most unusual. If a finger is rubbed lightly along a row of flowers, many pollinia will stick (very firmly) to it.
Distribution:
W. & WC. Trop. Africa
References:
Encyclopedia of Cultivated Orchids Hawkes 1965; AOS Bulletin Vol 39 No 10 1970; AOS Bulletin Vol 48 No 2 1979; Angraecoid Orchids Stewart, Hermans, Campbell 2006; WCSP (2017). 'World Checklist of Selected Plant Families. 28.02-2017; http://apps.kew.org/wcsp/
Images:
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Photograph ©Gilles Grunenwald. Image used with kind permission. Photograph ©Gilles Grunenwald. Image used with kind permission. Photograph ©Gilles Grunenwald. Image used with kind permission. Photograph ©Gilles Grunenwald. Image used with kind permission. Photograph ©Gilles Grunenwald. Image used with kind permission. Photograph ©Gilles Grunenwald. Image used with kind permission.