Culms 17-50 cm. Blades 7-20 cm long, 5-11.5 mm wide, bases rounded, setaceous apically. Influorescence branches 1.5-10 cm, in whorls of 2-5, either subdigitate or on rachises up to 15 cm long. Spikelets 5.5-13 mm, oblong, serrate in outline, with 6-25 florets. Lower glumes 1.2-2.9 mm, linear-oblong, acute, mucronate; upper glumes 1.5-3 mm, lanceolate, acuminate, awn-tipped; lemmas 2-2.8 mm, narrowly ovate, keels scabrous, shallowly concave distally, midveins excurrent, forming stout, 0.3-0.9 mm awns; lateral-veins also slightly excurrent. Fruits ellipsoid; seeds blackish, rugose, finely granular. 2n = 36.
Acrachne racemose grows in areas of seasonal rainfall in tropical regions of Africa, Asia, and Australia. It has been found in Riverside County, California and may become established there.
"decumbent" is not a number.