Innocent Weed, Spiny Burrgrass, Burrgrass, Gentle Annie
Introduced annual grass to 90cm tall. Leaves with a sheath at the base, sheath margins hairy, ligule a fringe of hairs 0.6-1.7mm long. Leaves flat, 6-19cm long, 3-8mm wide, hairless or hairy or rough, tapering to a fine point. Spikelets (2-3 per burr) straw-coloured or purplish, 6-12mm long. Seeds a hairy burr with many sharp spines. Mature seed groups cylindrical. Noxious weed Wentworth Shire. Declared plant in SA. Noxious weed Vic.
Short 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 pages 72-73
PlantNET description with line drawing of burr and photo of dried specimen: http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Cenchrus~longispinus
ausgrass2 description with line drawings of seeds: http://ausgrass2.myspecies.info/content/cenchrus-longispinus