AFRICAN

ORCHIDS

Gastrorchis tuberculosa (Thouars) Schltr., Repert. Spec. Nov. Regni Veg. Beih. 33: 169 (1924).
Homotypic Synonyms:
Limodorum tuberculosum Thouars, Hist. Orchid.: t. 31 (1822).
Bletia tuberculosa (Thouars) Spreng., Syst. Veg. 3: 744 (1826).
Phaius tuberculosus (Thouars) Blume, Mus. Bot. 2: 181 (1856).
Heterotypic Synonyms:
Phaius tuberculatus Blume, Coll. Orchid.: t. 11 (1858).
Phaius warpuri Weathers, Gard. Chron., III, 29: 82 (1901).
Description:
Rhizome climbing, short, emitting small pseudobulbs, short, concealed in the leaves, not more than 25 mm tall and 4 mm wide basally, hidden by its sheaths and leaves for several years after flowering. Leaves 5-6 per bulb, longly petiolate, petiole vaginiform, heavily costulate, equaling a third the length of the limbus: limbus narrowly lanceolate (30-60 x 2-3 cm), very attenuate toward both ends from the center, acute apically, striate-pleated and 3-5 veined, more projecting and of a paler color below. inflorescence equaling the leaves or .slightly longer, peduncle generally 6 times longer than the cluster; cluster 6-8 flowered and 10-15 cm tall, bracts very cauducous, of pure white, narrowly lanceolate. Sepals widely oval lanceolate (32-44 x 14-16 mm), apiculate, of pure white and 7 veined. Petals slightly smaller (24 x 10 mm), equally white. Labellum widely flat, obscurely trilobed, lateral lobes glabrous; provided basally with 3 projecting crests, slightly verrucose, 5 mm long raised and truncate apically, the median canaliculate, and behind with 2 crests of numerous white hairs, arranged in 4 rows, the external rows being shorter than the internals; lateral veins in the crests slightly thicker; with a yellow callus in the form of a V at the very base. Column white, 18 mm tall. — In the eastern forests the labellum is yellow sprinkled with a large number of red spots, with a single spot of violet near the base and the front margins of the median lobe white, coloration very different, according to the description by Rolfe (in Orch. Rev .,IX (1901), 43, from these plants in cultivation.
Habitat:
Terrestrials or semi-terrestrials; in eastern forests; flowering in November.
Distribution:
EC. & E. Madagascar
References:
Flora of Madagascar: vascular plants: 49th family, Orchids / by H. Perrier de La Bathie; published under the auspices of the government of Madagascar and under the direction of H. Humbert; English revision and translation by Steven D. Beckman; Orchids of Madagascar Hermans, Du Puy, Cribb & Bosser 2007; Field Guide to the Orchids of Madagascar Cribb & Herman 2009
Images:
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In culture In culture In culture In culture
Gastrorchis tuberculosa 01 Gastrorchis tuberculosa 02 Gastrorchis tuberculosa 03 Gastrorchis tuberculosa 04
Photograph© Lourens
Grobler. Image used
with kind permission.
Photograph© Lourens
Grobler. Image used
with kind permission.
Photograph© Lourens
Grobler. Image used
with kind permission.
Photograph© Lourens
Grobler. Image used
with kind permission.