AFRICAN

ORCHIDS

Platycoryne latipetala var. grandiflora (Summerh.) Geerinck, Bull. Jard. Bot. Natl. Belg. 52: 345 (1982).
Homotypic Synonyms:
Platycoryne grandiflora Summerh., Kew Bull. 13: 65 (1958).
Description:
Herba terrestris, erecta, 30-50 cm. alta, fere omnino glabra; tubera et radices non visa. Caulis rectus vel leviter flexuosus, teres vel leviter angulatus, basi 1-2 mm. diametro, basi cataphyllis vaginantibus pluribus sparse pubescentibus obtectus, superne laxe foliatus, apice in inflorescentiam pseudo-umbellatam terminans. Folia 4-5 ; inferius ± patens, basi vaginans, lanceolatum vel oblanceolatum, 4-9 cm. longum, I- 1-5 cm. latum, acutum; superiora + adscendentia vel ad caulem adpressa, vaginantia, internodiis multo breviora, anguste lanceolata, acuta, sursum decrescentia; omnia folia chartacea. Inflorescentia pseudoumbellata, I-3-flora; rhachis brevissima, usque ad I cm. longa; bracteae herbaceae, imbricatae, lanceolatae, acuminatae, usque ad 2 cm. longae, ovario pedicellato breviores. Flores erecti vel sub-erecti, lutei; pedicellus cum ovario interdum leviter arcuatus vel curvatus, 2-3 cm. longus. Sepalum intermedium erectum vel leviter recurvatum, late elliptico-lanceolatum, apice rotundatum apiculatum, 15-17 mm. longum, 7.5-8.5 mm. latum, convexum, quinquenervium; sepala lateralia patentia, oblique anguste elliptico-lanceolata vel anguste lanceolata, apice obtusa vel subacuta, 16-18.5 mm. longa, 5.5-6.5 mm. lata, subquinquenervia. Petala erecta, oblique falcatim vel valde curvatim ligulato-lanceolata vel lanceolata, apice acuta, 15.5-18 mm. longa, 5-5.5 mm. lata, sepalo intermedio agglutinata, subquinquenervia, sup erne textura crassiora ; omnia tepala nervis anastomosantibus. Labellum deflexim porrectum, anguste ellipticum vel oblanceolato-ellipticum, apice rotundatum, 13-15 mm. longum, mm. 4-5 latum, plurinervium; calcar dependens, leviter incurvatum, dimidio basali anguste cylindricum, dimidio apicali modice inflatum, apice ipso angustatum subacutum, 20-26 mm. longum. Anthera erecta, apice subacuta, circiter 5 mm. alta, loculis parallelis, canalibus incurvatis gracilibus circiter 2-5 mm. longis, auriculis oblongis rugulosis. Stigmata porrecta, fusiformi-clavata, apice ± acutata, 4-4.5 mm. longa ; rostellum erectum, 5 mm. altum, antheram valde superans ; lobus intermedius ovatus, acutus, circiter 3-5 mm. longus et 2-2-5 mm. latus, lobi laterales breviores, incurvati, circiter 1.25 mm. longi, apice truncati ; ovarium leviter pluri-sulcatum.
Help wanted to an English translation, please write to me, if you know where this can be found.
Habitat:
Note:
This striking species is characterised by the large flowers with spreading lateral sepals, the few-flowered inflorescences, the tall broad rostellum middle-lobe and the long pointed stigmas. In general floral structure it falls clearly into the genus but is rather aberrant in appearance. It is most closely allied to Platycoryne latipetala Summerh., described above, but differs in the larger flowers, narrower more acute petals and longer spur.
Distribution:
Zaïre

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Platycoryne megalorrhyncha Summerh., Bull. Misc. Inform. Kew 1933: 250 (1933).
Description:
Herba terrestris, gracilis, omnino glabra, 20-30 cm. alta. Caulis foliatus, erectus, teres, basi cataphyllis paucis acutis vaginantibus instructus. Folia lanceolata vel lineari-lanceolata, acutissima, basi caulem amplectentia, usque 5 cm. longa et 9 mm. lata, superior minora. Racemus 3-4 cm. longus, circiter 2 cm. diametro, dense 6-7-florus; bracteae lanceolatae, subaristato-acuminatae, ovario pedicellato saepius breviores, usque 2 cm. longae. Flores suberecti, ovario pedicellato circiter 1-7 cm. longo. Sepalum intermedium ovatum, acutum, carinato-concavum, 7 mm. longum, 4-5 mm. latum; sepala lateralia oblique oblongo-lanceolata, subacuta, 7.5 mm. longa, 2.5 mm. lata. Petala e basi latiore falcatim ligulata, acuta, 6-5 mm. longa, I mm. lata. Labellum simplex, anguste linguiforme, carnosum, marginibus recurvatis, 6-5 mm. longum, 1-3 mm. latum (explanatum); calcar dependens, cylindricum, dimidio superiore clavato-inflatum, obtusum, 14 mm. longum. Anthera erecta, obtusa, 3-5 mm. alta, canalibus porrectis crassiusculis 2-5 mm. longis. Brachia stigmatifera crassa, apice ovata dilatata, 2-5 mm. longa, antherae canales paulo excedentia. Rostelli lobus intermedius e basi latiore oblongo-lanceolatus, acutus, 2-4 mm. longus, 1.2 mm. latus; lobi laterales basi latissimi ab intermedio sinu lato rotundato sejuncti.
Help wanted to an English translation, please write to me, if you know where this can be found.
Habitat:
Note:
The large rostellum is placed in front of and is quite distinct from the column which it overtops. The front lobe widens at the base and the margin curves downwards almost to the apex of the anther canals, it therefore being very difficult to delimit the front and side lobes. The stigmata are widened at the apex into flattened somewhat concave ovate receptive surfaces. P. tenuicaulis Rolfe has a similar type of rostellum but the middle lobe is smaller and the anther canals much longer; the stigmata are also differently shaped and smaller.
Distribution:
Nigeria to Cameroon

 

 

 

 

 

 

Platycoryne brevirostris Summerh., Kew Bull. 13: 68 (1958).
Description:

Terrestrial herb 15–30 cm tall; tubers 10–15 × 6–10 mm, ovoid or ellipsoid, sparsely tomentose. Leaves 5–8, the lowermost sheathing with 2–4 suberect leaves clustered above these, up to 5 × 0.4 cm, linear or linear-lanceolate, acute; the remaining 2–3 spaced along the stem. Inflorescence 1.5–6 cm long, laxly 2–7-flowered.Flowers orange or yellow-green, suberect. Ovary and pedicel 15–20 mm long; bracts 7–17 mm long. Dorsal sepal erect, 4.5–5 × 3 mm, elliptic, slightly incurved; lateral sepals 5–6 × 2–2.5 mm, obliquely elliptic-oblong. Petals erect, c. 4.5 × 1.5 mm, curved lanceolate-ligulate, adnate to dorsal sepal. Lip deflexed or slightly incurved, 3-lobed at about halfway, 3.7–5 mm long, 2 mm wide across lobes; mid-lobe 2–4 × 1 mm, side lobes 0.2–1.2 × 0.3 mm; spur 15–18 mm long, slightly swollen at apex. Anther 3–4 mm high; canals 2.5 mm long. Stigmatic arms c. 1.5 mm long. Rostellum 2.5 mm long; mid-lobe c. 0.4 mm high; side lobes 1 mm long, relatively long and narrow.
Habitat:

Dambo and granite outcrops, in marshy ground over late rite or rock
Notes:

This species resembles Platycoryne trilobata but has smaller flowers.
Distribution:

Angola to Zambia

Platycoryne affinis Summerh., Kew Bull. 13: 61 (1958).
Description:

Slender terrestrial herb 20–40 cm tall; tubers c. 15 × 7 mm, ellipsoid, pubescent. Leaves 3–5, ± evenly spaced along the stem, the largest up to 5 × 0.5 cm, linear-lanceolate. Inflorescence 1.5–4 cm long, fairly laxly 2–4-flowered.Flowers yellow or yellow-green, erect or suberect. Pedicel and ovary 2.5–3 cm long; bracts 7–21 mm long. Dorsal sepal erect, 5–6 × 3–5 mm, broadly ovate, acute, convex; lateral sepals deflexed, 5–6.5 × 2–2.5 mm, obliquely lanceolate. Petals 4–5.5 × 2–3 mm, obliquely triangular or oblong-lanceolate, not adnate to dorsal sepal but attached to column at base. Lip 3.7–4.7 × 2–2.7 mm, ovate or elliptic-ovate, entire but sometimes with obscure lobes at base, fleshy; spur 15–25 mm long, slightly swollen at apex. Anther 2–3 mm high, apiculate, slightly incurved; canals 2 mm long. Stigmatic arms 2 mm long; rostellum c. 3 mm high, the side lobes shoulder-like, much shorter than mid-lobe.
Habitat:

Wet vlei 1360–1450 m.
Notes:

This species resembles Platycoryne protearum but may be distinguished from it by the usually smaller flowers with free petals, and by the broader lip sometimes with obscure lobes. The species seems prone to producing deformed flowers.
Distribution:

Zimbabwe

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:
Click on each image to see a larger version.

Habitat/In situ 
Platycoryne buchananiana 01 
Photograph© Warren
McCleland. Image used
with kind permission.