Barnyard Grass, Cockspur Grass
Introduced annual grass to 1.5m tall. Leaves with a hairless sheath at the base. Ligule absent. Leaves flat, 0.5-35cm long, 4-20mm wide, hairless or slightly hairy, the lower surface smooth or rough, edges smooth or rough, tapering to a fine point. Spikelets greenish to purple, 2-4mm long. Seeds pointed or with 1 short awn, in groups of 2-4. Mature seed groups cylindrical, eventually spreading.
Description and photo in G.M. Cunningham, WE Mulham, PL Milthorpe and J H Leigh (1981 and later printings) Plants of Western New South Wales page 89
ausgrass2 description with photos: http://ausgrass2.myspecies.info/content/echinochloa-crusgalli