Disa tripetaloides

Description

Disa tripetaloides is a species of orchid that grows along the edges of streams in South Africa. This is one of the smaller species in the genus Disa in the section Disa. There are populations that come from the winter-rainfall areas of South Africa, and summer-rainfall areas of South Africa. It is also one of the four commonly grown species of Disa in cultivation. The other three being Disa aurata, Disa cardinalis, and Disa uniflora. Disa tripetaloides is able to reproduce sexually and asexually. Asexual reproduction occurs by means of creating offshoots along the base of the plant and on stolons. Disa is a genus of flowering plants in the family Orchidaceae. It comprises about 182 species.Most of the species are indigenous to tropical and southern Africa, with a few more in the Arabian Peninsula, Madagascar, and Réunion. Disa bracteata is naturalised in Western Australia, where the local name is "African weed-orchid. The genus Disa was named by P.J. Bergius in 1767. It was named after Disa, the heroine of a Swedish legend. The plants grow from a fleshy tuberous root which is a source of maltodextrins which are used as a sugar substitute. Some species attain a height of 90 cm. The flowers are solitary or arranged in racemes. The petals and the lip are small. The flowers consist essentially of the sepals. The flowers range in color from very light to dark red. The first molecular phylogeny of the genus involved comparison of nuclear ribosomal ITS1, 5.8S rDNA, and ITS2 sequences, and showed that Herschelia and Monadenia were nested within a paraphyletic Disa. In Genera Orchidacearum volume 2, Disa and Schizodium compose the subtribe Disinae of the tribe Diseae. After that volume was published in 2001, molecular phylogenetic studies showed that Schizodium is nested within Disa. Schizodium comprises only six species, all endemic to South Africa. In a classification of orchids that was published in 2015, Chase et alii placed Schizodium in synonymy under Disa. They also defined the subtribe Disinae as consisting of Pachites, Disa and Huttonaea. This version of Disinae is probably not monophyletic, but was created as a holding classification, to avoid the unnecessary designation of subtribes before further studies can clarify the relationships of these three genera.