Annual sowthistle
Sonchus oleraceus, Sonchus asper
Importance
Common in all crops, woodlands and wasteland.
1. Seedlings of the various species are difficult to separate. In this stage, they differ from perennial sowthistle in that the blade of the first true leaf is cut away abruptly at the stalk.
2. Young plants of both species form a thistle-like rosette. Smooth sowthistle leaves are soft, not spiny whereas those of the prickly sowthistle are stiff, with prickly, spiny teeth.
3. An upright annual
