Xanthium spinosum L.

Family: Asteraceae, Tribe: Heliantheae

Pertinent Synonyms & Notes (particularly those used in California; go to GRIN for other synonyms)


Pertinent Common Names (particularly those used in California; go to GRIN for other common names)

spiny cocklebur

Primary Disseminule Type

spiny bur

Description (diagnostics are in brown)

Disseminule a spiny bur consisting of a hardened receptacle tightly enclosing two cypselae.

Bur cylindrical, body minutely glandular and sparsely hairy, yellowish-green to tan, 10–15 mm long x 4–10 mm diameter, with scattered spines, two chambers and 1–2 inconspicuous straight beaks (0.5–1 mm long, one beak often degenerate) at apex. Spines slender, ca. 2–3 mm long, ± straight and then prominently hooked at tip, glabrous.

Similar Species

Xanthium strumarium

Risk Assessment (codes in yellow or red indicate cause for concern; assessments are current as of mid-2011; click AUQP, NZBORIC, or NZBPI for access to the most recent versions of these databases and possible assessment changes)