AFRICAN

ORCHIDS

Platycoryne buchananiana (Kraenzl.) Rolfe in D.Oliver & auct. suc. (eds.), Fl. Trop. Afr. 7: 257 (1898).
Homotypic Synonyms:
Habenaria buchananiana Kraenzl., Bot. Jahrb. Syst. 19: 247 (1894).
Heterotypic Synonyms:
Habenaria kitondo De Wild., Ann. Mus. Congo Belge, Bot., IV, 1: 23 (1902).
Habenaria stolzii Kraenzl., Bot. Jahrb. Syst. 48: 386 (1912), nom. illeg.
Habenaria kitimboana Kraenzl., Bot. Jahrb. Syst. 51: 375 (1914).
Habenaria ipyanae Schltr., Bot. Jahrb. Syst. 53: 493 (1915).
Platycoryne kitondo (De Wild.) Summerh., Kew Bull. 11: 219 (1956).
Description:
A terrestrial herb 2-6.5 dm. high, glabrous except for the roots; tubers ellipsoid to cylindrical-ellipsoid, 1.5-2.5 cm. long, 5-15 mm. in diameter, tomentose. Stem erect, often somewhat flexuous, slender to rather stout, with leaves scattered along its length, terete or slightly angular. Leaves 5-9, the lowermost often reduced to a sheath, the remainder ± adpressed or the lower ones somewhat spreading, lanceolate, acute, the largest 2.5-9 cm. long, 5-13 mm. broad, the uppermost similar to the bracts. Inflorescence relatively short, 1.5-5.5 cm. long, 2-3.5 cm. in diameter, densely (1-)4-12(-16)-flowered. Bracts broadly lanceolate, acute or acuminate, 1-2 cm. long, about equalling the pedicel with ovary. Flowers suberect, pale yellow to deep orange; pedicel with ovary straight or slightly curved, 1-2 cm. long. Dorsal sepal erect, very convex and forming a hood with the petals, broadly elliptical-ovate, 5-8.5 mm. long, 4.5-7 mm. broad; laterals deflexed, obliquely elliptical- or oblong-lanceolate, apiculate, 5-9 mm. long, 2-3 mm. broad. Petals erect, adherent to the dorsal sepal, narrowly or ligulate lanceolate, curved, obtuse or subacute, 3.5-7.5 mm. long, 1-3 mm. broad. Lip inflexed, ligulate or elliptieal-ligulate, fleshy, convex, obtuse, 5-8.5 mm. long, 1-2 mm. broad; spur dependent, swollen in the apical half, 1-1.8 cm. long. Anther erect, apiculate, ± 4 mm. high, loculi parallel, canals porrect, 2-3 mm. long. Stigmas horizontal or slightly decurved, thick with swollen truncate ends, 2-3 mm. long; rostellum placed in front of the anther, the middle lobe narrow, acute, variable in length, sometimes overtopping the anther, the side lobes porrect with parallel sides.
Habitat:
Shallow soil over rocks or marshy grassland; 550—1850 m.
Phenology:
Flowering in December-June.
Notes:
This species is similar to Platycoryne lisowskiana Szlach., from which it differs in arrangement of inflorescence and position of the rostellum middle lobe versus anther. In Platycoryne buchananiana the inflorescence is dense, head-like and the rostellum midlobe is placed in front of the anther, whereas in Platycoryne lisowskiana the inflorescence is elongate and lax and rostellum mid-lobe is adnate to the anther. Another species which can be confused with Platycoryne buchananiana is Platycoryne heterophylla Summerh. The latter is characterized by lax inflorescence and leaves gathered at the base of the stem. Platycoryne buchananiana was given from the Republic of Congo by Sita & Mout-sambote (1988).
Cultivation:
Not in cultivation.
Distribution:
Guinea, Cameroon, the Republic of Congo, the Democratic Republic of Congo (Zaire), Burundi, Tanzania, Zambia, Malawi, Zimbabwe.
References:
Orchidaceae of West-central Africa, vol. 1, Gdansk University Press Gdansk 2010; 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; Flora of tropical Africa [1897-98 v. 7 (1-3)]: Page 572
Images:
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Habitat/In situ  Habitat/In situ Habitat/In situ Habitat/In situ
 Platycoryne buchananiana (Kraenzl.) Rolfe 01 Platycoryne buchananiana (Kraenzl.) Rolfe 02 Platycoryne buchananiana (Kraenzl.) Rolfe 03 Platycoryne buchananiana (Kraenzl.) Rolfe 04
Photograph© Biodiversity
and Landscape Unit.
Image used with kind
permission.
Photograph© Biodiversity
and Landscape Unit.
Image used with kind
permission.
Photograph© Biodiversity
and Landscape Unit.
Image used with kind
permission.
Photograph© Biodiversity
and Landscape Unit.
Image used with kind
permission.