Sonchus oleraceus L.
Family: Asteraceae
common sow-thistle, field sow-thistle
Sonchus oleraceus image
Matthew L. Wagner  
Etymology: Sonchus: the Greek name for sowthistle
Plants: erect, annual, 4"-80" tall, mostly hairless forb with milky juice
Leaves: alternate, arrow-shaped bases clasping but not curving around the stem, toothed to pinnately-divided, mostly soft with edges only slightly prickly; lower leaves with deep lobes and often with a triangular end-segment; upper leaves smaller and less divided
Flowers: head 1/2"-1" wide with yellow ray flowers; inflorescence of several heads in open, branched clusters; blooms July-Oct.
Fruits: wrinkled, dry seed faintly 3-5 ribbed on each side
Habitat: disturbed sites
Conservation Status: Introduced - naturalized