Thelymitra, commonly known as sun orchids, is a genus of more than 100 species of plants in the orchid family, Orchidaceae. Unlike most other orchids, sun orchids lack a highly modified labellum and all three petals are similar in size, shape and colour. The column is, however highly modified and usually has prominent wings or glands which are helpful in identifying the species. Most sun orchids close their flowers at night, in cloudy or cool weather, giving rise to their common name. The scientific name means "woman's hood" and refers to the hooded column present in most, but not all species. Most species are endemic to Australia although some are found as far from there as the Philippines and Indonesia. The type species, Thelymitra longifolia, the first to be formally described, was coll