Beard orchid | |
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C. platychilus on Black Mountain in the A.C.T. | |
Scientific classification | |
Kingdom: | Plantae |
(unranked): | Angiosperms |
(unranked): | Monocots |
Order: | Asparagales |
Family: | Orchidaceae |
Subfamily: | Orchidoideae |
Tribe: | Diurideae |
Subtribe: | Thelymitrinae |
Genus: |
Calochilus R.Br. |
Calochilus, commonly known as beard orchids, is a genus of about 30 species of plants in the orchid family, Orchidaceae. Beard orchids are terrestrial, herbs with a single leaf at the base of the plant, or no leaves. Their most striking feature is a densely hairy labellum, giving rise to their common name. Beard orchids, unlike some other Australian orchids, do not reproduce using daughter tubers, but self-pollinate when cross-pollination has not occurred. Most species occur in Australia but some are found in New Zealand, New Guinea and New Caledonia.
Orchids in the genus Calochilus are terrestrial, perennial, deciduous, sympodial herbs with a few inconspicuous, fine roots and a pair of egg-shaped tubers lacking a protective fibrous sheath. The tubers produce replacement tubers on the end of a short, root-like stolons. There is either a single, linear, fleshy, convolute leaf, usually channelled, sometimes triangular in cross section, or there is no leaf.
The inflorescence is a raceme with from one to many resupinate flowers. The flowering stem usually has sheathing bracts, which often appear leaf-like. The sepal is broad, erect, dished and often forms a horizontal hood over the column. The sepals are similar to, but usually narrower than the dorsal sepal. The petals are shorter and narrower than the sepals and often have a hook-like tip. As is usual in orchids, one petal is highly modified as the central labellum. The labellum is longer than all the other parts of the flower, oblong near its base, triangular near the tip and densely covered with purple or metallic-coloured hairs, short near the base of the labellum increasing in length towards its tip. The sexual parts of the flower are fused to the column, which is short and broad with broad wings on its sides. The base of the column forms two rounded collars around the stigma, each often with an eye-like spot. Flowering time depends on the climatic region where the species is found and the fruit that follows flowering is a non-fleshy, dehiscent capsule containing up to 500 seeds.