Greek aer – air; angos – vessel; a possible allusion to the long spur on the labellum of some species.
Epiphytic or rarely epilithic herbs, monopodial. Stems usually short, sometimes long, erect, simple, lacking pseudobulbs, aerial roots abundant. Leaves in 2 ranks, often oblanceolate, irregularly 2-lobed at tip. Inflorescences axillary racemes, long or short, arching. Flowers resupinate, 1-many, medium sized to large, white, often tinged with green, yellow or pink. Sepals and petals similar, free, usually narrow, spreading or curved backwards. Labellum entire, often similar to petals, with a long or short spur at base. Column short and stout or moderately long and slender. Pollinia 2, with 1 or 2 stipes.
About 50 species from Africa, Madagascar and Sri Lanka.
Mainly white spidery flowers with a long basal spur on labellum and beaked rostellum.
Source: (2005). Orchidaceae. In: . Horticultural Flora of South-eastern Australia. Volume 5. Flowering plants. Monocotyledons. The identification of garden and cultivated plants. University of New South Wales Press.