Dipodium
Dipodium, commonly known as hyacinth orchids, is a genus of about forty species of orchids native to tropical, subtropical and temperate regions of south-east Asia, New Guinea, the Pacific Islands and Australia. It includes both terrestrial and climbing species, some with leaves and some leafless, but all with large, often colourful flowers on tall flowering stems. It is the only genus of its alliance, "Dipodium". Description. Orchids in the genus "Dipodium" are perennial, terrestrial herbs or climbers/epiphytes. Many species, particularly in eastern Australia are leafless mycoheterotrophs. Others have medium-sized to very large leaves that are parallel -veined and have entire margins. The flowers are arranged in a raceme with very few or up to fifty large, often colourful flowers. These may be fragrant or odourless, are white, pink, purple, yellow or green, often with spots or blotches. The sepals and petals are free from and similar to each other. The labellum projects forwards and has three lobes with a central band of colourful hairs. Each flower has two pollinia that are supported on two stipes. Dehiscent capsules, produced after flowering, hold the seed which is released when the capsule splits longitudinally along six seams. Between 30  and 500 seeds are produced per capsule. Taxonomy. The genus was formally described in 1810 by Scottish botanist Robert Brown in "Prodromus Florae Novae Hollandiae et Insulae Van Diemen". The name "Dipodium" is derived the Greek words "di" (two) and "podia" (little feet), a reference to the two stipes supporting the pollinia. Distribution and habitat. Hyacinth orchids are found in Malaysia, the Philippines, Indonesia, the Solomon Islands, the New Hebrides, New Caledonia, New Guinea and Australia where eleven species are endemic. They occur in a range of habitats from coastal lowlands to ranges and tablelands. Ecology. It is thought that  the flowers attract native bees and wasps through floral mimicry. Uses. An infusion of the leaves of "Dipodium pandanum" is traditionally drunk in Bouganville to help relieve respiratory infections. Use in horticulture. Leafless hyacinth orchids are impossible to grow in cultivation but "D. pandanum" is easy to grow in warm climates. Species. The following is a list of described species in the genus "Dipodium", recognised by the "World Checklist of Selected Plant Families" apart from "Dipodium punctatum" which is recognised as a species in Australia (rather than as a synonym of "Dipodium squamatum").