Diurideae is a tribe of orchid in the subfamily Orchidoideae. The tribe has a centre of diversity in Australia, with occasional dispersals to New Zealand, New Calendonia, Papua New Guinea, and Malesia.

Infratribal classification

While Diurideae itself is a well-supported clade, relationships among its constituent subtribes remain equivocal, likely due to the confounding effects of incomplete lineage sorting. The tribe has previously been subdivided into nine subtribes: Acianthinae; Caladeniinae; Cryptostylidinae; Diuridinae; Drakaeinae; Megastylidinae; Prasophyllinae; Rhizanthellinae; and Thelymitrinae. However, phylogenomic analyses have shown that Megastylidinae is best subsumed into an expanded Drakaeinae. Rhizanthellinae has also been treated as a synonym of Prasophyllinae.

Evolution and Ecology

The tribe is estimated to have originated in the Eocene (c. 52Ma), with a crown age of c. 46 Ma. The tribe is known for an unusually high number of species which engage in sexually deceptive pollination, particularly in the subtribes Caladeniinae and Drakaeinae. Additionally, members of the Diurideae appear to have a high degree of fungal symbiont specificity, with orchid species partnering with an average of only one to two fungal species.

Genera

Diurideae contains about 40 accepted genera. Chase et al. (2015) accepted the following genera. Some have since been combined.