Description:

• Perennial herbs, terrestrial, lithophytic or epiphytic; green or rarely saprophytic; with underground root tubers, corms, rhizomes, or above-ground pseudobulbs
• Leaves cauline or basal; alternate, often distichous, rarely opposite; mostly simple and variously lanceolate to ovate; occasionally all reduced to scales, often fleshy, sheathing at base
• Inflorescences racemes or panicles, rarely 1-flowered; flowers bisexual, occasionally unisexual, usually irregular
• Sepals (outer perianth lobes) 3, mostly coloured and petaloid, median one often galeate and frequently spurred
• Petals (lateral inner perianth lobes) 2, frequently rather simple and similar to sepals; sometimes different and with colour markings and various callosities
• Lip (median inner perianth lobe) often lobed and spurred, occasionally galeate; usually facing down (resupinate position), rarely facing up (nonresupinate)
• Stamen 1 in all African genera, united with style to form a gynostemium (column); with 2 erect, forward-bent (incumbent) or reflexed thecae which may be adjacent or separated by wide connective; thecae frequently covered by distinct cap (operculate); pollen usually cohering in 2, 4 or 8 pollinia; pollinia mealy-soft, sectile (consisting of individual pollen massulae) or hard and often waxy; naked or with pollinium stalks (2 types: caudicle = stalk produced within the anther, often yellow and translucent, elastic and sticky; stipe = nonsticky rostellum tissue); attached to 1 or 2 viscidia (sticky glands) of rostellum
• Stigma entire, 2-lobed or consisting of two separate areas; pad- or cushion-like, situated in cavity or sometimes on stalks in front of gynostemium; borne in upper or lower part of gynostemium, usually facing forwards or upwards, rarely downwards or sideways; upper part of median stigma lobe normally transformed into nonreceptive rostellum which bears viscidia
• Ovary inferior, 1-locular in all African genera, with many ovules on 3 parietal placentae
• Fruit a capsule; opening with 6 valves
• Seeds many, minute and fusiform, 0.2-2 mm long

Nomenclature:

• Orchidaceae
  • Rolfe: 3 (1912, 1913)
  • Schelpe: 279 (1962)
  • Schelpe: 1 (1966)
  • Sölch: 1 (1967)
  • Harrison: 1 (1972)
  • Stewart et al.: 1 (1982)
  • Linder & Kurzweil: 1 (1999)

Distribution & Notes:

• Global: Genera ± 800, species ± 20 000; cosmopolitan, but infrequent in dry areas or at high altitudes
• Southern Africa: Genera 52, species ± 466

References:

• HARRISON, E.R. 1972. Epiphytic orchids of southern Africa. Natal Branch of the Wildlife Society of Southern Africa
• LINDER, H.P. & KURZWEIL, H. 1999. Orchids of southern Africa. A.A. Balkema, Rotterdam
• ROLFE, R.A. 1912, 1913. Order CXXXI. Orchideae. Flora capensis 5,3
• SCHELPE, E.A. 1962. An annotated check-list of the epiphytic orchids of South Africa with keys to the genera and species. Journal of South African Botany 28
• SCHELPE, E.A. 1966. An introduction to the South African Orchids. Purnell & Sons, Cape Town, Johannesburg
• SÖLCH, A. 1967. Orchidaceae. Prodromus einer Flora von Südwestafrika 166
• STEWART, J., LINDER, H.P., SCHELPE, E.A. & HALL, A.V. 1982. Wild orchids of southern Africa. Macmillan, Johannesburg

Resources:

• Classification of Orchidaceae
• Natural Key to Orchidaceae subfamiies, tribes and genera
• Artificial Key to Orchidaceae genera

• Orchidaceae genera: