(Tridens muticus var. elongatus)
Rough tridens is a found throughout the Rio Grande plains, but is most common in the northern portions of South Texas. Plants are very similar in appearance to slim tridens, but can be differentiated by having taller seed stalks. Rough Tridens produces large amounts of seed consumed by many wildlife species. Cultivated production of this species is difficult due to its preference for shallow, dry soils. This species is also a poor competitor with most exotic grasses. Evaluation of several accessions of this species was discontinued in 2006.