Monographs Details: Olyra longifolia Humb., Bonpl. & Kunth
Authority: Maguire, Bassett. 1969. The botany of the Guayana Highland-part VIII. Mem. New York Bot. Gard. 18: 1-290.

Olyra surinamensis Hochst. ex Steud., Syn. PI. Glum. 36. 1854.

A common species of Olyra found along rivers and streams, or wet areas in tropical rain forests of the Amazonian region. It can be distinguished from all other species of the genus by the pitted surface of the female lemma which is pubescent toward the summit, and the disposition of male and female spikelets on separate racemelike branches, inserted at about the same point on the axis. A later synonym, 0. surinamensis, is found on most herbarium specimens of this species.