Oryzopsis racemosa of Michigan Flora.

Usually in moist rich deciduous forests and forested dunes, sometimes in disturbed places; less often associated with jack pine and oak.

The awn of the lemma may be as long as 23 mm in this species, although usually less than 20 mm. The widest leaf blades are usually 1 cm or more broad.

Romaschenko et al. (2011) provide the rationale for segregating Patis from Oryzopsis and Piptatheropsis. This is a grass genus with an eastern Asian-eastern North American disjunct distribution, similar to Brachyelytrum, Diarrhena, and Zizania.