Plants annual. Culms 10-45 cm, compressed. Blades 6-25 cm long. Panicles digitate, with (1)2-3 branches; branches 1-6(8) cm long, 5-14 mm wide, oblong. Spikelets 8-10 mm, with 5-9(11) florets. Glumes unequal; lower glumes 2-3 mm; upper glumes 3-4 mm; lemmas 4-5 mm. 2n = 18.

Eleusine tristachya was originally thought to be native to tropical Africa and introduced into tropical America, but it occurs in Africa only as a rare adventive. It is now considered to be native to tropical America. In the 1800s and early 1900s, it was found on ballast dumps at various ports and transportation centers in the United States. More recently, it has been found as a weed in the Imperial Valley of California (Hilu 1980). All records of collections outside of California appear to be historical, with no populations persisting. That from Texas, for instance, was made from a plant growing in a range management area associated with one of the Texas A&M University farms. Although not deliberately cultivated, it probably was an escape. The species has not been collected since in Texas.