AFRICAN

ORCHIDS

Pterygodium Sw., Kongl. Vetensk. Acad. Nya Handl. 21: 217 (1800).
Synonyms:
Ommatodium Lindl., Gen. Sp. Orchid. Pl.: 365 (1838).
Anochilus (Schltr.) Rolfe in W.H.Harvey & auct. suc. (eds.), Fl. Cap. 5(2): 280 (1913).
Description:
Plants terrestrial, with testicu1ar tubers; stem slender to robust, to 1.5 m tall; leaves cauline, 1-to many, linear to lanceolate. Inflorescences terminal, up to 500 mm long, 1-numerous-flowered; bracts elliptic to ovate. Flowers resupinate or not, shallowly hooded, pale green to yellow or white, sometimes flushed red or marked with purple, usually strongly scented; ovary 8-21 mm long. Lateral sepals spreading to reflexed Petals linear to subrotund, entire to crenulate or erose, adnate to the median sepal. Lip narrowly linear to de1tate or rounded, with or without side lobes, bearing an e1ongate appendage. Anther thecae horizontal or rare1y erect, situated at the comers of a long horseshoe-shaped connective; pollinia 2, sectile; stigma apparent as 2 pads which are derived from the median stigma lobe.
Distribution:
Tanzania, S. Africa
Notes:
A genus of 18 species, all except P. ukingenseSchltr. (Tanzania) in southern Africa. Kurzwei1 et al. (1991) showed that there are two subgroups in the genus .Reflexed bracts were identified as the synapomorphy of the clade that comprises the two distinct groups formally recognized as sect. Magnum and sect. Ommatodium. Ro1fe (1913) separated Ommatodium volucris because of its erect anther. Pterygodium magnum (sect. Magnum) was previously inc1uded in Corycium (Stewart et al. 1982), but its oven flowers and the erect and elongate lip appendage suggest that it is better placed in the genus Pterygodium.
The second clade comprises the two sections Anochilus and Pterygodium. The former comprises two species previously separated into the genus Anochilus because of their doubly resupinate flowers with their lips facing upwards (Rolf e 1913; Stewart et al. 1982). Few cauline leaves and lax, few-flowered inflorescences characterize sect.Pterygodium which contains the majority of species in the genus.
Pterygodium Section Magnum Kurzweil & H.P. Linder
Very robust terrestrial plants with cauline and lanceolate leaves. InfIorescence dense; bracts much longer than the flowers, deflexed. Flowers resupinate, large, rather open; lip appendage solid and elongate; anther thecae ascending.
Pterygodium Section Ommatodium (Lindl.) Kurzweil & H.P. Linder
Slender plants with few cauline leaves. Inflorescence dense or lax; bracts reflexed. Flowers resupinate, shallowly concave; tip 3-lobed with a cup-or funnel-shaped appendage; thecae erect.
Pterygodium Section Anochilus Schltr.
Robust plants with few cauline, lanceolate leaves. Inflorescence dense. Flowers medium-sized orlarge, doubly resupinated, shallowly cup-shaped; lip superior, with a flat, pendent claw and a solid and elongate appendage; thecae horizontal or semi-pendent.
Pterygodium Section Pterygodium
Slender to robust plants with few cauline leaves. Inflorescence lax, few-flowered. Flowers large, resupinate, cup-shaped, mostly yellow; lip appendage erect or reflexed, elongate and solid; the-cae horizontal or semi-pendent.
Bibliography and References:
Hennessy EF. 1981 Orchids of Africa. Pterygodium cooperi Rolfe. Amer. Orchid Soc. Bull., 50. (6): 674 - 676 (1981)
Kurzweil H, Linder HP, Chesselet P. 1991 The phylogeny and evolution of the Pterygodium-Corycium complex (Coryciinae, Orchidaceae). Pl. Syst. Evol. 175. (3-4): 161-223 (1991)
Kurzweil H, Linder HP, Stern WL, Pridgeon AM. 1995 Comparative vegetative anatomy and classification of Diseae (Orchidaceae). Bot. J. Linn. Soc. 117. 171-220.
Kurzweil H. 1991 The unusual structure of gynostemium in the Orchidaceae, Corycinnae. Bot. Jahrb. 112. (3): 273-293 (1991)
Linder HP, Kurzweil H. 1994 The phylogeny and classification of the diseae (Orchidoideae: Orchidaceae). Ann. missouri Bot. Gard. 81. 687-713.
Linder HP, Kurzweil H. 1996 Ontogeny and phylogeny of Brownleea (Orchidoideae: Orchidaceae). Nordic J. Bot. 16. 345-357.
Linder HP. 1988 Taxonomic notes on some orchids from the south-western Cape Province, South Africa. S. Afr. J. Bot. 54. (4): 496-500 (1988)
Reid C. 1993 Pterygodium hallii; western Cape; Orchidaceae. Flow. Pl. Afr. 52. (2): pl.2071 (4p.) (1993)