AFRICAN

ORCHIDS

Platycoryne ambigua (Kraenzl.) Summerh., Hooker's Icon. Pl. 33: t. 3239 (1934).
Homotypic Synonyms:
Habenaria ambigua Kraenzl., Bot. Jahrb. Syst. 28: 175 (1900).
Description:
A terrestrial herb 1.5-4 dm. high, glabrous except for the roots; tubers ellipsoid, ± 1 cm. long and 0.5 cm. in diameter, ± tomentose. Stem erect, slender, flexuous, with leaves scattered along its length, terete or angular. Leaves 4-7, the lowermost sometimes reduced to a sheath, the remainder erect or suberect, linear, acute, the largest 4-10 cm. long and 4-7 mm. broad, the upper ones smaller. Inflorescence up to 10 cm. long, 2.5-4 cm. in diameter, rather loosely (1-)3-8-flowered. Bracts leafy, lanceolate, acuminate, 1-2.5 cm. long, the lower ones longer than the pedicel with ovary. Flowers curving outwards, yellow or scarlet; pedicel with ovary curved, ± 2 cm. long. Dorsal sepal curved forwards, resembling a sickle from the side, very convex, lanceolate, acuminate, 1.3-1.7 cm. long, ± 6 mm. broad; laterals deflexed, narrowly lanceolate, very acute, 1-1.5 cm. long, ± 2.5 mm. broad. Petals erect, adherent to the dorsal sepal, linear, acute, 11-15 mm. long, nearly 1.5 mm. broad. Lip generally curved upwards from just above the base, linear, obtuse, 1-1.4 cm. long, ± 1.5 mm. broad; spur dependent, swollen in the apical part, 1.2-1.6 cm. long. Anther erect, subacute, ± 6 mm. high, canals porrect or slightly curved upwards, ± 4.5 mm. long. Stigmas horizontal, swollen at the apex, fleshy, ± 3 mm. long; rostellum placed in front of the anther, 4.5 mm. high, 3-lobed in the upper half, the middle lobe oblong-lanceolate, acute, 3 mm. long, the side lobes shorter, obliquely triangular, truncate.
Habitat:
Wet grassland in depressions or near streams; 1100-1650 m.
Cultivation:
Not in cultivation.
Distribution:
Tanzania
References:
Flora of Tropical East Africa Summerhayes Orchidaceae Part 1 1968; African Orchids: XXV V. S. Summerhayes, Kew Bulletin, Vol. 13, No. 1 (1958), pp. 57-87+ii; ENDEMIC PLANT SPECIES OF ZIMBABWE ANTHONY MAPAURA, Kirkia, Vol. 18, No. 1 (2002), pp. 117-149; Miscellaneous Notes Bulletin of Miscellaneous Information (Royal Botanic Gardens, Kew), Vol. 1935, No. 1 (1935), pp. 57-64
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