Monographs Details:
Authority:

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Family:

Asteraceae
Scientific Name:

Sonchus oleraceus L.
Description:

Species Description - Annual 1–20 dm from a short taproot, glabrous except sometimes for a few spreading gland-tipped hairs on the invols and peduncles; lvs pinnatifid to occasionally merely toothed, soft, the margins only weakly or scarcely prickly, 6–30 × 1–15 cm, all but the lowermost ones prominently auriculate, the auricles well rounded but eventually sharply acute; lvs progressively less divided upward and ± reduced; heads several in a corymbiform infl, relatively small, 1.5–2.5 cm wide in fl; invol 9–13 mm in fr; fls 80–250 per head; cor-tube about equaling the ligule; achenes 2.5–3.5 mm, transversely rugulose and evidently to rather obscurely 3–5-ribbed on each face; 2n=32, 36. A cosmopolitan weed, native to Europe. July–Oct.

Common Names:

common sow-thistle