The largest subtribe of Diurideae is Caladeniinae,which has a predominantly Australian distribution. As circumscribed by Dressler, the subtribe included ten genera, a number that has grown to fourteen in recent treatments. The status of the four segregate genera, Praecoxanthos, Drakonorchis, Elythranthera, and Cyanicula, has been questioned by some authors. The current study assessed the monophyly of Caladeniinae, the segregate genera, and the genus Caladenia itself. Three genera that have been included in the subtribe, Leporella, Lyperanthus and Rimacola, should be excluded from Caladeniinae based on sequence data. Our study supports the removal of Praecoxanthos from Caladenia, as suggested by Hopper and Brown on the basis of morphological characters. Praecoxanthos is sister to a clade composed of Glossodia, Elythranthera, Cyanicula, Caladenia, and Drakonorchis. Elythranthera is well-supported and appears sister to Glossodia. Cyanicula is likewise very well-supported and is sister to Caladenia s.str.. Drakonorchis, on the other hand, is embedded within the more derived species of Caladenia. Like some members of Drakaeinae, Drakonorchis has a thynnid wasp pseudocopulation pollination syndrome, showing that this complex suite of adaptations has evolved more than once within Diurideae.

Key words: Australia, Caladeniinae, Diurideae, ITS, Orchidaceae