South American Barnyard Grass, Barnyard Grass
Introduced annual grass to 2m tall or sprawling. Leaves with a hairless sheath at the base. Ligule absent. Leaves 12-60cm long, 5-25mm wide, flat, hairless, with rough edges and a tapered point. Spikelets green, 2-4mm long. Seeds usually with 1 awn 3-10mm long. Mature seed groups cylindrical to 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
PlantNET description with line drawings and photos of dried specimens: http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Echinochloa~crus-pavonis
ausgrass2 description with photos (as Echinochloa cruspavonis): http://ausgrass2.myspecies.info/content/echinochloa-cruspavonis