A. sterilis is a stout broad-leaved annual grass resembling cultivated oats in general appearance (Ivens, 1989).
Stem to 1.5 m height, tufted, erect, rarely geniculate, not branching, not rooting at the nodes, nodes sometimes hairy. Leaf blades 60 cm long, 6-14 mm wide, 30-40 times as long as wide, linear, not hairy. Ligule 2 mm long, membranous, truncate, sheath often on lower leaves. Inflorescence an equilateral or slightly one-sided panicle, 15-45 cm long, 8-25 cm wide. Spikelets with 2-5 florets of which only the lowest has a basal scar, pedicelled, disarticulating above the glumes, but not between the florets. Glumes equal, 30-50 mm long, 9-11 nerved. Lemmas 15-40 mm long, 7 nerved, bidentate, the uppermost awnless, the lower two with a 5-8 cm long bent and twisted dorsal awn (Hafliger and Scholz, 1981; Ivens, 1989; Stace, 1997).
The sub-species sterilis differs from sub-species ludoviciana by the larger size of some reproductive parts (spikelets with 3-5 florets; longer glume 32-45 mm; lemmas 25-33 mm; ligule greater than 5 mm) (Stace, 1997).
Learn more »
Wikipedia page »