Restionaceae R. Br. Three of the four families occur in North America north of Mexico, Mayacaceae, Commelinaceae and Xyridaceae. They share more features in common with the Xyridaceae than the Commelinaceae. The order does form the basal unit within the subclass as outlined by Cronquist. As a group they have well defined sepals and petals.
Pollination is primarily entomophilous even though the flowers are without nectaries or nectar.
The fruits are generally dry capsules but can be fleshy and berry-like. The majority of the species are terrestrial herbs, although species of the Xyridaceae are commonly found in marshy places, and Mayaca is an aquatic. The circumscription of the Commelinales has been restricted by all of the recent authors. Reveal and Takhtajan confine the order to include only the Commelinaceae. Thorne adds the Haemodoraceae, Pontederiaceae and Philydraceae.