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Ministry of Agriculture, Food and Rural Affairs

Common Groundsel

Scientific Name: Senecio vulgaris L.

Other Names: séneçon vulgaire, séneçon commun

Family: Composite or Aster Family (Compositae

General Description: Annual, reproducing only by seed.

Habitat: Common groundsel occurs throughout Ontario, often very abundantly, in gardens, row crops, waste places and roadsides.



  • Erect or somewhat reclining
  • Often branched
  • 10- 60 cm (4- 24 in.) high
  • Smooth
  • Somewhat fleshy


  • Alternate (1 per node)
  • Slightly fleshy
  • Variable in shape from smooth and almost without teeth to shallowly or deeply lobed, with the lobes finely to coarsely and irregularly toothed
  • Lower leaves stalked
  • Upper ones stalk-less and often clasping the stem


  • Heads stalked in clusters at the end of stems and branches
  • Each head 5- 10 mm (1/5- 2/5 in.) across
  • Cylindrical or conic
  • Without ray florets
  • Disk florets yellowish
  • Involucral bracts (surrounding each flower head) small, overlapping, usually with distinct black tips
  • Seeds small, short-hairy, with a prominent, white, hairy pappus
  • Flowers from June to late autumn

Often Confused With
Common Ragweed Seedling (The lobes of the leaves of common ragweed are much more deeply dissected.)

Groundsel flowers Common groundsel Common groundsel Common groundsel seed head Common groundsel Common groundsel
Click to enlarge.