Scientific Name: Senecio vulgaris

Common Name: common groundsel

Other Common Names: old-man-in-the-spring

Habit: This erect winter annual flowers from April through October. Depending on climate, it may also act as a summer annual, or a biennial. 3 to 4 generations may develop during one growing season.

Leaves: The alternately arranged leaves have deeply lobed margins, and are irregularly tooted. Leaves may be sparsely hairy, although most are hairless. The upper leaves are directly attached to the stem while the lower leaves have a short petiole.

Identifying Characteristics: This plant contains pyrrolizidine alkaloids which are harmful to horses, cattle, swine, and even humans, causing liver damage and possibly, death. Smaller herbivores such as rabbits and goats are resistant to the plant's effects.

Flower Seed Head: The yellow flowers occur in clusters in the ends of stems. Each disk-shaped flower can grow up to 1 cm in diameter.

Seed Fruit: Seeds develop in reddish brown to gray-brown achenes. The achenes have soft white hairs, and when in clusters, form puff balls like that of the Dandelion, easing dispersion by wind.

Where Found: This weed can be found in moist nutrient rich areas, such as lawns and flowerbeds.

  • Life cycle: winter annual

  • Milky sap: Not Present

  • Plant type: Herb

  • Thorns: Not Present

  • Plant family: Asteraceae

  • Leaf arrangement: alternate

  • Leaf shape: lance

  • Ochrea: Not Present

  • Leaf margin: serrated

  • Stem hairs: no hairs; has hairs

  • Flower color: yellow

  • Growth habit: upright and nonwoody

  • Stem: round or oval

  • Leaf structure: simple

  • Leaf hairs: no hairs; has hairs

  • Flower diameter: pencil

  • Flower symmetry: radial symetery

  • Root structure: taproot; fibrous

  • Leaf stalk: none