Pterygodium

Pterygodium is a genus of terrestrial perennials in the Orchidaceae or orchid family, growing from small root tubers. The leaves are few, elliptic to lanceolate, growing on the stems.

The inflorescence is a loose to dense raceme of mostly resupinate flowers above lanceolate bracts. The cup-shaped flowers are white, yellow or green. The three sepals are free, the median one adhering to the asymmetrical, ovate, lateral petals in forming a shallow hood over the rest of the floral parts. The lateral sepals spread or are reflexed. The lip is entire or divided into two or three lobes with variously shaped appendages near its base, where it is attached to the column.

The central floral column called the gynostemium is short and expanded laterally. It comprises both the male and female parts and is complex in structure. There is a two-lobed anther, mostly horizontal or pendent, containing two pollinia. The capsule is cylindrical or obovoid and ribbed.

The flowers are strongly fragrant, mostly pollinated by oil-collecting bees of the Rediviva genus, also the pollinators of the diascias.

The genus of Corycium was added into Pterygodium after molecular investigations into floral morphology during 2012 or shortly after that.  Fourteen of the sixteen erstwhile Corycium species are from South Africa.

Phylogenetic relationships are explored in studies building on earlier ones, establishing a gradually clarifying account of how the ancestry of our current species evolved. When the cladistic analysis of flower shape, leaf anatomy, pollen, seed and more bring new insights about shared ancestry, plant names and classification sometimes change. Bear with it.  

There is some confusion as to the number of Pterygodium species. At the time of writing (2025), SANBI's Red List comprises 32 in South Africa. Manning (2009) says 18 species, 17 of which in South Africa. He then still had the South African Corycium species separately at 14. Liltved and Johnson gave the Pterygodium number of species as 20 in 2012, as well as 16 Corycium species, all South African apart from one in Malawi and one in Tanzania. Maybe a total of 36 or 37 is as close as can be at this time.

Many of the plants flower best in the year after fire, others continually, unless overgrown.

The plant in picture may be Pterygodium pentherianum (Liltved and Johnson, 2012; Leistner, (Ed.), 2000; Vlok and Schutte-Vlok, 2015; Manning, 2009).