Rhodora 45: 388 (1943) APNI
Tufted annual. Culms basally decumbent, to 50 cm high. Leaves mostly glabrous, rarely sparsely hairy; blade flat to inrolled, to 10 cm long and 5 mm wide; sheath keeled, often purplish; ligule c. 1 mm long. Inflorescence a spike, 3–7 cm long, the axis flattened and flexuose; involucre (burr) 7–10 mm long, with a basal series of bristles or much finer spines and several uneven rows of stout, apically retrorsely barbed bristles, the longest 5 mm long or more; bristles numbering 40 or more in total; body of the burr shortly hairy. Spikelets 1–3 per burr, 6–7.5 mm long; lower glume 1-nerved, acute, 1.5–4 mm long; upper glume 5-nerved, acute, 4.5–6 mm long; lower floret male, its lemma equal to or slightly longer than upper glume, palea subequal to lemma; fertile lemma as long as spikelet, 5-nerved, ovate, acuminate, papery; palea subequal to lemma. Flowers Jan.–Apr.
*GipP, *Glep, *Gold, *GGr, *LoM, *MuF, *MuM, *MSB, *NIS, *VRiv, *VVP, *Wim. Naturalised in all mainland States, widely worldwide. Probably native to North America and South America. In Victoria, a common and troublesome weed on sandy soils in the far north-west (Mildura, Swan Hill, Ouyen areas), particularly in irrigated farmland, a sporadic weed elsewhere (e.g. noted in railyards at Yarrawonga and Cranbourne).
|Bioregion||Occurrence status||Establishment means|
|Victorian Volcanic Plain||present||introduced|
|Murray Scroll Belt||present||naturalised|
|Northern Inland Slopes||present||introduced|
|New South Wales|
|Australian Capital Territory|