Flora of North America species comparison

The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Xanthium spinosum

Xanthium strumarium

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

Canada cocklebur, cocklebur, common cocklebur, lampourde glouteron, rough cocklebur, rough cockleburr
Habit Plants 10–60(–120+) cm; nodal spines usually in pairs, simple or 2–3-partite, 15–30+ mm. Plants 10–80(–200) cm; nodal spines 0.
Leaves

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.

petioles 20–100(–140+) mm;

blades suborbiculate to ± pentagonal or deltate, 4–12(–18+) × 3–10(–18+) cm, sometimes palmately 3–5-lobed, abaxial faces green, hirtellous.
Burs

10–12(–15+) mm.

10–30+ mm.
2n

= 36.

= 36.

Xanthium spinosum

Xanthium strumarium
Phenology Flowering Jul–Oct. Flowering Jul–Oct.
Habitat Damp or seasonally wet, alkaline soils, waste places, margins of agriculture Damp or seasonally wet, often alkaline, soils, waste places, margins of agriculture
Elevation 10–1000 m (0–3300 ft) 10–2000 m (0–6600 ft)
Distribution
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
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NS; ON; PE; QC; SK; Mexico; Central America; South America [Widely introduced in Old World]
[WildflowerSearch map]
[BONAP county map]
Discussion

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.)

Recognition of a dozen or more taxa (treated as species, subspecies, varieties, and/or forms) has been proposed for plants treated together here as Xanthium strumarium. Bases for the various taxa mostly involved subtle differences in the burs.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 21, p. 19. FNA vol. 21, p. 19.
Parent taxa Asteraceae > tribe Heliantheae > subtribe Ambrosiinae > Xanthium Asteraceae > tribe Heliantheae > subtribe Ambrosiinae > Xanthium
Sibling taxa
X. strumarium
X. spinosum
Synonyms X. ambrosioides, X. spinosum var. inerme X. americanum, X. chasei, X. chinense, X. curvescens, X. cylindricum, X. echinatum, X. echinellum, X. globosum, X. inflexum, X. italicum, X. orientale, X. oviforme, X. pensylvanicum, X. speciosum, X. strumarium var. canadense, X. strumarium var. glabratum, X. varians, X. wootonii
Name authority Linnaeus: Sp. Pl. 2: 987. (1753) Linnaeus: Sp. Pl. 2: 987. (1753)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



Type/paste one or more Latin names into the boxes above; matching taxa will show up below the box as you type. You can use the up/down arrow keys to move through the list.

(If the plant you're looking for doesn't show up in the auto-complete list, that means it either isn't described in Flora of North America yet, or it's listed under a synonym. And please note that Flora of North America is still missing several plant families, including Apiaceae, Boraginaceae, and Polemoniaceae.)

Choose a data source: Flora of North America, OregonFlora, UW Burke Herbarium

The species comparison tool is brought to you by:
Northwest Wildflowers