Angraecum umbrosum P.J.Cribb, Kew Bull. 40: 407 (1985).
Homotypic Synonyms:
Angraecum linearifolium P.J.Cribb in I.F.la Croix & al., Malawi Orchids 1: 32 (1983), nom. illeg.
Description:
Slender, pendent epiphytic herb; stem c. 30 cm long, flattened, almost winged. Roots 1–1.5 mm in diameter, arising all along the stem. Leaves distichous, 6–12 cm × 2–4 mm, linear, falcate, acutely and unequally 2-lobed at the apex. Inflorescences arising along stem opposite leaf axils, 1-flowered but often with a second bud which aborts. Peduncle 5–20 mm long; pedicel and ovary 7 mm long with a sharp bend c. 5 mm from the base. Flowers pale yellow or yellow-green, less than 10 mm in diameter. Sepals 6–9 × 1.5–2 mm, linear-lanceolate, acute. Petals similar but slightly shorter and narrower. Lip 5–6 × 2–3 mm, very concave, acute, with a central raised callus at the base; spur 6–8 mm long, slightly swollen in apical half. Column less than 1 mm long.
Habitat:
In riverine and submontane forests at elevations of 1700 to 1900 meters .
Cultivation:
As given for the genus, cool growing epiphyte.
Notes:
Specimens from Zomba Mt., the type locality, look very distinctive with long, very narrow leaves and small flowers, but those from the northern region have slightly wider leaves and can be difficult to distinguish from Angraecum stolzii. Angraecum cultriforme, another closely related species, can usually be easily identified by its larger, longer spurred flowers and short, markedly falcate leaves with divergent lobes, but smaller flowered specimens, such as la Croix & Spurrier 779, are almost intermediate between Angraecum cultriforme and Angraecum stolzii.Angraecum stolzii has distinctive woody spurs where inflorescences arise in successive years, but Brenan 5, from Nchunga Falls in Zambia, which otherwise matches Angraecum cultriforme, has this feature. Angraecum cultriforme grows in hotter, more low-lying areas than Angraecum stolzii and Angraecum umbrosum, but it is possible that a detailed study would show that all belong to one variable species, in which case Angraecum stolzii would be the valid name.
Distribution:
Malawi, Known only from these localities
References:
Malawi Orchids La Croix 1983 as Angraecum linearifolium; African Orchids In the Wild and Cultivation La Croix 1997; Flora Zambesiaca Vol 11 Part 2 Pope 1998; Angraecoid Orchids Stewart, Hermans & Campbell 2006; WCSP (2017). 'World Checklist of Selected Plant Families. 28.01-2017; http://apps.kew.org/wcsp/
Images:
Click on each image to see a larger version.
| In culture |
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| Photograph© Lourens Grobler. Image used with kind permission. |
