The orchids of Timor: checklist and conservation status

A checklist of the Orchidaceae of Timor is presented, with emphasis on the eastern half of the island (East Timor), based on historical herbarium collections and recent botanical explorations. This list comprises 38 genera with 66 species, including 15 new genera and 32 new species records for this island. Moreover, four new species are described: Bulbophyllum sundaicum , Habenaria ankylocentron , Habenaria cauda‐porcelli , and Pterostylis timorensis . Of these, we consider the finding of a new species of Pterostylis to be especially noteworthy, because this species seems to be more closely related to certain Australian members of the genus than to the Malesian ones, suggesting earlier contacts of Timor with Australia. Four new synonyms are proposed: Calanthe veratrifolia var. timorensis J.J.Sm. (C. triplicata), Habenaria cornuta Span. (H. giriensis), H. grandis Benth. ex Ridl. (Peristylus goodyeroides), and H. mutica Span. (H. elongata). The best represented genus is Habenaria, with 13 species, followed by Dendrobium with four, and Bulbophyllum with three. Because of insufficient or sterile material, it was not possible to identify, or describe as new, 20 different taxa. The conservation status of the ten endemic species, plus six possible new undescribed species and two non‐endemic, but threatened, species, was assessed using the World Conservation Union (IUCN) criteria, and categories of threat were proposed. Seven endemic species are considered to be Critically Endangered and two Endangered. One of the nonendemic species is considered to be Critically Endangered, and the other Endangered. The survival of some of these species might be less insecure if an effective application of Regulation project N.2000/19 on protected areas (UNTAET/REG/2000/19) was implemented and maintained, because most of these species were collected in areas considered for protection under this Regulation. Further studies are required, however, in order to complete our knowledge of the diversity and population dynamics of this interesting part of Timor's biodiversity. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157 , 197–215.