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Weed Identification
Australia > > Spiny Burrgrass
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Spiny Burrgrass
Cenchrus longispinus |
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Alternative Name(s): Bohena Beauty, Gentle Annie, Innocent Weed.
Family: Poaceae.
Form: Grass
Origin: Native of North America.
Flowers/Seedhead: A cylindrical spike. Flowers summer and autumn.
Description: Erect or spreading tufted annual grass to 60 (rarely to 90) cm high. Stems may root at lower nodes, hairless. Leaves 3–7 mm wide, ligule a fringed membrane.
Distinguishing features: Distinguished by top of the spikelets protruding above the top of the burr (but still shorter than the spines); burrs 5–8 mm long usually with more than 40 spines that are almost circular in cross-section in the upper half and with base of larger spines rarely wider than 1 mm, without ring of smaller bristles around base of burr.
Dispersal: Spread by seed in burrs. Burrs are spread attached to animals, clothing and bags, and burrs float and are moved by water.
Confused With: Other Cenchrus species, see taxonomic texts for detailed distinguishing features.
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Grass with cylindrical spikes of burrs
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Notes: Common in arid areas on light soils. Burrs reduce the value of wool and make shearing hazardous. Spines of burrs also penetrate hides lowering hide value. Burrs are also a problem with drying of fruit on drying racks.
References:Noxious Weeds of Australia. W. Parsons and E. Cuthbertson, 1992, pages 97–100. Flora of NSW. G. Harden (ed), Vol. 4, 1993, pages500–502. Flora of Victoria. N. Walsh and T. Entwisle (eds), Vol. 2, 1994, pages 614–615.
Web References: Search Australian web sites for further information on this weed.
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Top: Burrs of Cenchrus longispinus
Bottom: Cenchrus incertus |
Burr showing slender & broad-based spinesphoto P.Abell |
