Canada Cockleburr

Xanthium strumarium L. Sp. PI. 987. 1753
Xanthium priscorum Wallr. Beitr. Bot. 1: 227. 1844.
Xanlhium antiquarian Wallr. Beitr. Bot. 1: 229. 1844.
Xanlhium abvssinicum Wallr. Beitr. Bot. 1: 230. 1844.
Xanthium discolor Wallr. Beitr. Bot. 1: 232. 1844.
Xanthium Roxburghii Wallr. Beitr. Bot. 1: 233. 1844.
Xanthium brevirostre Wallr. Beitr. Bot. 1: 235. 1844.
Xanthium slrumarium anliquorum Ball, Jour. Linn. Soc. 16: 503. 1878.
Stem somewhat branched, pubescent, 0.4-1.5 m. high; leaves 0.6-2.5 dm. long, the petioles
equaling or exceeding the blades; blades triangulate-deltoid, truncate or subcordate at the
base, 3-5-lobed, on both sides similarly colored and clothed with appressed strigose hairs;
body of the fruit ovoid, or swollen and subglobose, commonly greenish, pubescent, 0.8-1.4
cm. long; beaks straight or incurved at the apex, 1-2 mm. long, often standing apart; prickles
straight, hooked at the apex, glabrous above, more or less pubescent below, about 2 (rarely
3) mm. long.
Type locality: Europe.
Distribution: Adventive in Massachusetts and California; native of north-temperate and tropical regions of the Eastern Hemisphere.