Ambrosia acanthicarpa Hook.

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)

flatspine bur ragweed, annual bursage

Primary Disseminule Type

spiny bur

Description (diagnostics are in brown)

Disseminule a spiny bur consisting of hardened phyllaries tightly enclosing a single cypsela.

Bur ovoid to fusiform to obpyramidal, golden brown to dark purple, glabrous or puberulent, 3–8(10) mm long, with 6–30 scattered spines. Spines 2–4(5) mm long, sharp-pointed, flattened, ± straight.

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)