Annual sow-thistle
Scientific Name: Annual sow-thistle, Sonchus oleraceus L.
Other Names: Laiteron potager, Common annual sow-thistle, laiteron lisse, laiteron commun.
Family: Composite or Aster Family (Compositae)
General Description: Perennial, reproducing by seed and by spreading underground rhizomes.
Habitat: Annual sow-thistle occurs throughout Ontario in waste places, along fence lines, roadsides, around buildings and occasionally in gardens.
Stems & Roots
- The part of the leaf closer to the stem is very narrow.
- The base of the leaf clasping the stem has 2 angular or pointed lobes.
- All margins with small teeth and soft weak spines.
Flowers & Fruit
- Seed ridged lengthwise and each ridge has numerous small cross-wrinkles.
Often Confused With/Distinguishing Characteristics
Easily distinguished by having leaves which are deeply lobed with the terminal lobe being short, broad and rounded or triangular.
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