Common groundsel

Image by: James Altland, USDA-ARS
Common groundsels thick, fleshy green foliage is 2 to 4 inches in length, lacerate (irregularly lobed) and serrate.
Image by: James Altland, USDA-ARS
Image by: James Altland, USDA-ARS
Common groundsel flowers heads are 1/4 to 1/2 inch long, tubular, and yellow.
Image by: James Altland, USDA-ARS
Image by: James Altland, USDA-ARS
Common groundsel seeds are covered with a white cotton-like tissue called a pappus. This feature allows the seed to be carried
Image by: James Altland, USDA-ARS
Image by: James Altland, USDA-ARS
Upright branched habit of common groundsel.
Image by: James Altland, USDA-ARS
Senecio vulgaris
Family: 
Asteraceae
Life cycle: 
Annual
Habit: 
Plants are upright, branched, and can easily grow 18-24 inches tall. Young plants remain rosettes until reaching maturity. Foliage is green, 2 to 4 inches in length, lacerate (irregularly lobed) and serrate.
Flowers: 
Common groundsel flowers heads are 1/4 to 1/2 inch long, tubular, and yellow. Each flower head is composed of many individual disk flowers that make up the composite head. Each disk flower develops into a single seed.
Favorable environments: 
Container
Favorable environments: 
Field
Favorable environment notes: 
Groundsel can be found growing just about anywhere-along roadsides, landscape areas, gardens and most agricultural plantings. Areas of cool, moist, nutrient rich, cultivated soils encourage rapid growth and reproduction. Three to four generations can develop and thrive in these ideal conditions causing management issues for growers. In non-irrigated areas, or during long dry hot periods, common groundsel typically dies out.
Dissemination: 
When mature, seeds are covered with a white cottony material called pappus. This feature enables seed to travel long distances via wind dispersal.
Of interest: 
Common groundsel can develop flowers at a very small size. This necessitates post emergence control of escaped weeds soon after germination. Because of spring and summer irrigation practices, container and field nurseries offer ideal conditions for common groundsel. Over irrigation will encourage germination and proliferation of this common weed. Careful monitoring of water usage will be very beneficial in controlling common groundsel in the nursery setting.