Orchidaceae

Taxonomic status:Accepted

Occurrence status:Present

Establishment means:Native

Perennial, rarely annual, terrestrial, epiphytic or rock-dwelling herbs, arising from creeping-rhizome, annually renewed tuber or thickened rootstocks or rhizome; aerial stem may be swollen at base into pseudo-bulb, some with adventitious or aerial roots. Leaves parallel-veined or curviveined, entire, mostly basal, base of leaf sheathing or not; usually reduced to bracts or scales in saprophytic species. Flowers bisexual, zygomorphic, very rarely regular, in spikes, racemes or panicles, or solitary; perianth mostly petaloid, 6 segments in 2 whorls, free or variously joined, occasionally fused to form tube; if axis erect, labellum on upper side in young bud, in most cases pedicel twisting during development so that labellum is below column; sepals 3, often differentiated into dorsal sepal and 2 lateral sepals; petals 3, differentiated into 2 laterals petals and a labellum. Labellum modified greatly (in all genera but Thelymitra) in size and shape, often with outgrowths such as calli, hairs and fringes; nectary sometimes contained within spur or sac from labellum, or more rarely, the dorsal sepal. Column bearing both anther and stigma, a more or less erect, usually fleshy, prolongation of floral axis; anthers 1 or 2, 2-locular, turned inward, opening by longitudinal slits; pollen grains rarely free, usually aggregated in tetrads or in larger masses that are mealy, waxy or quite hard, one end of which may be extended into sterile part (caudicle); stigma borne on labellum-side of column, 2–3-lobed, median lobe sometimes replaced by sterile outgrowth (rostellum), part of which may be modified into a viscid disc (viscidium); ovary inferior, 1-celled with 3 parietal placentae, rarely 3-celled. Fruit a capsule, usually dehiscing by 3 or 6 longitudinal slits; seeds numerous and very minute, often drawn out at each end or rarely winged, without endosperm, embryo not differentiated.

World-wide distribution with over 850 genera and 25,000–35,000 species; over 190 genera and over 1,300 species in Australia, and 32 genera with over 300 species in Victoria.

Source: Entwisle, T.J. (1994). Orchidaceae. In: Walsh, N.G.; Entwisle, T.J. (eds), Flora of Victoria Vol. 2, Ferns and Allied Plants, Conifers and Monocotyledons. Inkata Press, Melbourne.
Updated by: Jeff Jeanes, 2015-07-30
 
Hero image
life Life
kingdom Plantae
phylum Tracheophyta
superorder Lilianae
order Asparagales
Higher taxa
family Orchidaceae
Subordinate taxa
genus Acianthus
genus Burnettia
genus Caladenia
genus Caleana
genus Calochilus
genus Chiloglottis
genus Corunastylis
genus Corybas
genus Cryptostylis
genus Cyanicula
genus Cyrtostylis
genus Dendrobium
genus Dipodium
genus Disa
genus Diuris
genus Eriochilus
genus Gastrodia
genus Glossodia
genus Leporella
genus Leptoceras
genus Lyperanthus
genus Microtis
genus Orthoceras
genus Pheladenia
genus Plectorrhiza
genus Prasophyllum
genus Pterostylis
genus Pyrorchis
genus Sarcochilus
genus Spiranthes
genus Thelymitra