| Xanthium spinosum L. |
| ASTERACEAE |
| spiny cocklebur, burweed, prickly burweed, spiny clotbur, dagger cocklebur, dagger weed, thorny burweed |
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Invasive, Problem species |
| Origin: Tropical America |
| Growth Form: Herb |
| Plant Description: Plant: Much-branched annual up to 1.2 m high; stems smooth, green or yellowish, armed with three-pronged spines.
Leaves: Blue-green, sparsely hairy above, densely white-woolly below, entire or three-lobed, ± lanceolate, up to 60 mm long x 20 mm wide.
Flowers: Greenish, inconspicuous in axils of leaves, October–April.
Fruit: Burs ± 10 mm long, green, with reddish, hooked spines, turning yellowish then brown. |
| Key Features: shorter, more branched habit but much narrower, divided, dark green leaves with a white underside and smaller burrs c.f. X. strumarium |
| Control: |
| Comments: |
More information:
Weeds & Invasive Plants Home Page
NRCS Plants Database
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Illustration
USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. Illustrated flora of the northern states and Canada.
Photo - plant
Gary A. Monroe @ USDA-NRCS PLANTS Database
Photo - fruit/spines/leaves
The Weeds Society of Western Australia
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| KEY |
 Confirmed (herbarium specimen) |
 Visual record |
 Suspected |
| Click on map grid square to view record information for each grid square. |
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