Sonchus arvensis L.

Family: Asteraceae, Tribe: Cicharieae

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)

perennial sowthistle

Primary Disseminule Type


Description (diagnostics are in brown)

Fruit a cypsela, narrowly elliptic to oblong, sometimes slightly curved and/or twisted, compressed, cross-section narrowly elliptic to 3- or 4-angled, (1.8)2.5–4.5 mm long x 0.6–1.5 mm wide x 0.3–0.6 mm thick. Surface brown, dull to faintly glistening, glabrous, transversely wrinkled (appearing tuberculate), longitudinally ribbed (ribs prominent, typically 8–10(16)). Pappus ± persistent, bristles 8–15 mm long (>3 times the length of the fruit body), numerous, fine, white.

Style base inconspicuous to cylindrical, whitish, apical scar (when pappus is removed) raised, 0.3–0.5 across.

Fruit attachment scar basal, a polygonal (4-segmented) cup with rim and cavity cream-colored.

Similar Species

Similar Species Comparison Chart

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)