ANNUAL SOW THISTLE
Scientific Name: Sonchus oleraceus L.
Other Names: Laiteron potager, Common annual sow-thistle, laiteron lisse, laiteron commun.
Family: Composite or Aster Family (Compositae)
General Description: Very similar to spiny annual sow-thistle in general appearance. Annual, reproducing only be seed. Whole plant with sticky white juice.
Habitat: It occurs in habitats similar to those of spiny annual sow-thistle. Occurs throughout Ontario in waste places, along fence lines, roadsides, around buildings and occasionally in gardens.
Seedlings
- Rosette
- Alternate leaves
- Cotyledons orbicular to oblong
Stems
- Erect
- 40 cm -1 m in height
Leaves
- The part closer to the stem very narrow
- The base clasping the stem with 2 angular or pointed lobes
- All margins with small teeth and soft weak spines
Flowers
- Yellow
- Small (2 cm in diameter)
- On stalks at the end of the stems
Seeds
- Ridged lengthwise
- Each ridge with numerous small cross-wrinkles
Often Confused With
Easily distinguished by having leaves which are deeply lobed with the terminal lobe being short, broad and rounded or triangular.
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