Thelasis carinata, commonly known as the triangular fly orchid,[1] is a plant in the orchid family. It is a clump-forming epiphyte or lithophyte that lacks pseudobulbs. There are groups of between two and six erect, flattened stems each with up to six leaves that have a ridged lower surface. Up to fifteen green and white flowers are arranged on a thin but stiff flowering stem. This orchid is found from Thailand to the southwest Pacific.
Thelasis carinata is an epiphytic or lithophytic herb with thin roots and flattened stems NaNsigfig=2NaNsigfig=2 long in groups of between two and six. Each stem has between three and six dark green, narrow oblong leaves NaNsigfig=2NaNsigfig=2 long and NaNsigfig=2NaNsigfig=2 wide. The leaves have a ridge on their lower side and their lower end sheaths the stem. Between six and fifteen green and white resupinate flowers NaNsigfig=2NaNsigfig=2 long and NaNsigfig=2NaNsigfig=2 wide are arranged along a thin but stiff flowering stem NaNsigfig=2NaNsigfig=2 long emerging from a leaf axil. The flowers are self-pollinating, tube-shaped near their bases and have an ovary that is triangular in cross section. The sepals are NaNsigfig=2NaNsigfig=2 long and 1.5sigfig=2NaNsigfig=2 wide, the lateral sepals about 4sigfig=2NaNsigfig=2 long and NaNsigfig=2NaNsigfig=2 wide and the petals are shorter and narrower than the sepals. The labellum is about 4sigfig=2NaNsigfig=2 long and 2.5sigfig=2NaNsigfig=2 wide and curves downwards. Flowering occurs between April and June.[2] [3]
Thelasis carinata was first formally described in 1825 by Carl Ludwig Blume who published the description in Bijdragen tot de flora van Nederlandsch Indië.[4] [5] The specific epithet (carinata) is a Latin word meaning "keeled".[6]
The triangular fly orchid usually grows on rocks and trees in humid, well-lit situations. It is found in Thailand, Borneo, Java, the Lesser Sunda Islands, Peninsular Malaysia, Maluku Islands, the Philippines, Sulawesi, Sumatra New Guinea, the Solomon Islands, Queensland, Australia, New Caledonia and Samoa. In Queensland it occurs between the Iron Range and McIlwraith Range.[7]