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clotbur, lampourde épineuse, spiny clotbur, spiny cocklebur, spiny cockleburr

Habit Plants 10–60(–120+) cm; nodal spines usually in pairs, simple or 2–3-partite, 15–30+ mm.

petioles 1–15(–25+) mm;

blades ± ovate to lanceolate or lance-linear, 4–8(–12+) × 1–3(–5+) cm, often pinnately 3(–7+)-lobed, abaxial faces gray to white, densely strigose.


10–12(–15+) mm.


= 36.

Xanthium spinosum

Phenology Flowering Jul–Oct.
Habitat Damp or seasonally wet, alkaline soils, waste places, margins of agriculture
Elevation 10–1000 m (0–3300 ft)
from FNA
AL; AZ; CA; CO; CT; DE; FL; GA; IA; ID; IL; IN; KS; KY; MA; MD; ME; MI; MO; MS; MT; NC; NE; NH; NJ; NM; NV; NY; OH; OR; PA; RI; SC; TN; TX; UT; VA; WA; WV; NB; ON; QC; SK; Mexico; Central America; South America; widely established in Old World
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Some authors have contended that Xanthium spinosum originated in South America and is introduced and/or naturalized everywhere else that it is found.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 21, p. 19.
Parent taxa Asteraceae > tribe Heliantheae > subtribe Ambrosiinae > Xanthium
Sibling taxa
X. strumarium
Synonyms X. ambrosioides, X. spinosum var. inerme
Name authority Linnaeus: Sp. Pl. 2: 987. (1753)
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