Diurideae

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. ^[1] The tribe has previously been subdivided into nine subtribes: Acianthinae; Caladeniinae; Cryptostylidinae; Diuridinae; Drakaeinae; Megastylidinae; Prasophyllinae; Rhizanthellinae; and Thelymitrinae.^[2] However, phylogenomic analyses have shown that Megastylidinae is best subsumed into an expanded Drakaeinae.^[1] Rhizanthellinae has also been treated as a synonym of Prasophyllinae. ^[2][1]

The tribe is estimated to have originated in the Eocene (c. 52Ma), with a crown age of c. 46 Ma. ^[1] The tribe is known for an unusually high number of species which engage in sexually deceptive pollination, particularly in the subtribes Caladeniinae and Drakaeinae.^[2][3] 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. ^[1][4]

Diurideae contains about 40 accepted genera.^[5] Chase et al. (2015) accepted the following genera.^[5] Some have since been combined.