Description: ### General
Annual herbs from a short taproot; stems erect, solitary, few-branched above, glabrous, hollow, exuding milky juice when broken, 0.1-1 m tall.
### Leaves
Basal leaves lacking; stem leaves alternate, weakly or scarcely prickly-margined, lowermost stalked, backward-swept pinnately cut to occasionally merely toothed, 6-30 cm long, 1-15 cm wide, uppermost lobed with sharply pointed ear-lke lobes.
### Flowers
Heads with strap-shaped flowers, several on sometimes glandular stalks in an open, flat- or round-topped inflorescence, relatively small, commonly 1.5-2.3 cm wide in flower; involucres 9-14 mm tall; involucral bracts lanceolate, tapering to a slender tip at the apex, glabrous except for some spreading, gland-tipped hairs; ray flowers yellow.
### Fruits
Achenes 2.5-3 mm long, with 3-5 evident to rather obscure longitudinal ribs on each face, cross-wrinkled; pappus of white hairlike bristles.
### Links
[Sow Thistle @ E-Flora BC](http://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Sonchus%20oleraceus)
Data provided by Permapeople.org under CC BY-SA 4.0 license. This work is also distributed under the same license.