AFRICAN

ORCHIDS

Platycoryne mediocris Summerh., Kew Bull. 13: 72 (1958).
Description:
A terrestrial herb 2-5 dm. high, glabrous except for the roots; tubers ellipsoid or almost globose, 0.5-2 cm. long, 5-12 mm. in diameter, sparsely tomentose. Stem erect, often somewhat flexuous, slender, terete, with leaves scattered along its length. Leaves 6-10, the lowermost 1-2 reduced to sheaths, the remainder suberect or ± spreading, the largest 2.5-6 cm. long and 4-9 mm. broad, the upper smaller. Inflorescence short, rarely up to 5 cm. long, 2.5-3.5 cm. in diameter, densely 2-5(-7)-flowered. Bracts broadly lanceolate, acuminate, 7-20 mm. long, shorter than the pedicel with ovary. Flowers curving outwards or suberect, orange; pedicel with ovary somewhat curved, 1.5-2.5 cm. long. Dorsal sepal erect, broadly ovate, very convex, acute, 7-11 mm. long, 5-6 mm. broad; laterals deflexed, obliquely oblong-lanceolate, acute, 8-10 mm. long, 2-3.5 mm. broad. Petals erect, adherent to the dorsal sepal, much curved, ligulate-lanceolate, 7-10 mm. long, ± 2-5 mm. broad. Lip deflexed, 3-lobed at the base, 6.5-10.5 mm. long, 1-2 mm. broad, the side lobes tooth-like or triangular, spreading, scarcely I mm. long; spur dependent, swollen in the apical third, 1-1.7 cm. long. Anther erect, apiculate, 3-5 mm. tall, canals porrect, 1-2 mm. long. Stigmas horizontal, thick, club-shaped, 2-3 mm. long; rostellum erect, nearly as long as the anther, the middle lobe narrowly triangular, just over 2 mm. long, the side lobes truncate, shorter.
Habitat:
In damp grasslands and Brachystegia woodlands.
Phenology:
Flowering in June.
Notes:
This species might be confused with Platycoryne heterophylla because of similar form of the lip. Both species differ from each other, however, in the size of the flowers and arrangement of the leaves along the stem.
Cultivation:
Not in cultivation.
Distribution:
Cameroon, Central African Republic, the Democratic Republic of Congo (Zaire), Burundi, Tanzania, Zambia, Malawi and Zimbabwe. Alt. 200-1750 m.
References:
Orchidaceae of West-central Africa, vol. 1, Gdansk University Press Gdansk 2010; African Orchids: XXV V. S. Summerhayes, Kew Bulletin, Vol. 13, No. 1 (1958), pp. 57-87+ii; The Southern African Orchid Flora: Composition, Sources and Endemism H. P. Linder, Journal of Biogeography, Vol. 32, No. 1 (Jan., 2005), pp. 29-47; Flora Zambesiaca Vol 11, Part 1, (1995) Author: I. la Croix and P.J. Cribb
Images:
Click on each image to see a larger version.

Habitat/In situ  Habitat/In situ  Habitat/In situ 
Platycoryne mediocris 01  Platycoryne mediocris 02  Platycoryne mediocris 03 
Photograph© Nicholas
Case Wightman Image
used with kind
permission.
 
Photograph© Nicholas Case
Wightman Image used with kind
permission.
 
Photograph© Nicholas Case
Wightman Image used with kind
permission.