Genus Platycoryne

Platycoryne protearum var. protearum
Description:
Plants from the Nyika Plateau in Malawi tend to be small, the inflorescence usually 1-flowered and the flowers predominantly green.
Habitat:
Wet grassland and marshy or seepage areas amongst rocks 1050–2200 m.
Distribution:
Tanzania to S. Trop. Africa
References:
La Croix, I. & Cribb, P.J. (1995). Orchidaceae (Part 1) Flora Zambesiaca 11(1); La Croix, I. et al. (1991). Orchids of Malawi A.A. Balkema, Rotterdam Page 105.
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Platycoryne alinae Szlach., Fl. Cameroun 34: 202 (1998).
Description:
Tubers 2, up to 3 cm long, 0.6 cm in diameter, narrowly cylindrical, thick. Stem 20-30 cm tall, erect, rather delicate, glabrous. Leaves 4-5, distributed along stem, 4.5-5.5 cm long, lanceolate, acute, erect, decreasing in size up the stem. Inflorescence up to 10 cm long, 1-2-, occasionally 3-flowered, lax. Flowers large, resupinate, yellow to yellow-orange. Floral bracts up to 20 mm long, broadly ovate-elliptic, shortly acuminate. Pedicel 40-45 mm long, very slender, erect, twisted. Ovary up to 20 mm long, slender, slightly arcuate. Dorsal sepal 16 mm long, 13 mm wide, orbicular-ovate, subacute, cochleate, with elevated thick apical keel outside, erect. Petals 15 mm long, 6 mm wide, obliquely oblong-ovate, subacute, with small, ca. 0.6 mm long lobule at the base, broadly united with the gynostemium. Lateral sepals 16 mm long, 7 mm wide, obliquely elliptic above narrow base, apex subacute, semi-cucullate, thickened. Lip 15 mm long, 4 mm wide, ligulate, strongly thickened towards truncate apex, with inconspicuous, triangular basal wings. Spur 9-9.5 cm long, 2 mm in diameter, narrowly cylindrical, slightly swollen in the apical fifth, blunt. Anther ca. 3 mm tall, rostellum middle lobe massive, equal in length to connective, in front of it, auricles probably lacking.
Habitat:
No data. June.
Notes:
This species apperas to be related to Platycoryne macroceras Summerh. from Zambia and the Democratic Republic of Congo (Zaire), but it differs by its longer spur, larger perianth segments, petals with small basal lobules and longer antherophores.
Cultivation:
Not in cultivation.
Distribution:
Cammeroon. Alt. 1650 m.
References:
Orchidaceae of West-central Africa, vol. 1, Gdansk University Press Gdansk 2010
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Platycoryne lisowskiana Szlach. & Kras, Polish Bot. J. 53: 103 (2008).
Description:
Tubers one or two, 1-2 cm long, 0.4-0.6 cm in diameter, narrowly ellipsoid. Stem 23-35 cm tall, erect, delicate, glabrous. Leaves 5-7, more or less basal, erect to sub-erect, the remaining ones scattered along stem, 3.0-6.5 cm long and 0.60.9 cm wide, narrowly lanceolate, acute, suberect, decreasing in size towards the apex of the stem, the last upper ones bract-like, ca 2 cm long, the lower 1-2 sheath-like. Inflorescence 5.0-6.5 cm long, 2-5-flowered, lax. Flowers small, resupinate, yellow to orange. Floral bracts 7-17 mm long, broadly ovate to semi-orbicular, apiculate, glabrous. Pedicel 7-15 mm long. Ovary 15-20 mm long, erect, cylindrical. Dorsal sepal 7-10 mm long, 6 mm wide, semi-orbicular, apiculate, coch-leate, glabrous, nerves unbranched. Petals 6-9 mm long, 2 mm wide, entire, linear-lanceolate, falcate, acute or subacute. Lateral sepals 8-10 mm long, 2.5-3.5 mm wide, obliquely oblong-lanceolate, obtuse to subacute. Lip 7-8 mm long, 1.5 mm wide, ligulate, obtuse, rather fleshy with revolute margins, pendent, occasionally with small basal tooth. Spur 15-20 mm long, 1 mm in diameter, narrowly cylindrical, blunt to subacute. Anther 3.3 mm tall, the connective apiculate, the rostellum middle lobe adnate to the anther, slightly longer than the connective.
Etymology:
Dedicated to Professor Stanislaw Lisowski (1926-2002), an eminent Polish scientist, who botanized extensively in Africa.
Habitat:
Dry area in thin clayey loam on laterite, seasonally inundated, sand on sandstone shield in meadows. Flowering May-July.
Note:
Platycoryne lisowskiana differs from the closely related Platycoryne megalorrhyncha Summerh. in having leaves shorter than the internodes, the spur longer than the ovary, anthero-phores as long as the rostellum middle lobe, and the rostellum middle lobe delicate, filiform.
Distribution:
Central African Rep.
References:
Platycoryne lisowskiana (Orchidaceae, Orchidoideae), a new species from the Central African Republic, Polish Bot. J. 53: 103 (2008).
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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.
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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