Coefficient of Conservatism:
Coefficient of Wetness:
R. W. Smith
This is the commonest, Old World, pinnatifid-leaved, weedy groundsel in Michigan. It has evidently been long established here, having been collected as early as 1838 from a roadside in Calhoun Co. Now a local weed in gardens, lawns, nurseries, and cultivated fields; in disturbed sites, including sidewalk cracks, parking lots, bulldozed areas, shores.
The involucre in this species and S. sylvaticus are ca. (4–) 6–7 mm long, generally a bit longer than in Jacobaea vulgaris and about the same length as the native S. eremophilus Richardson, which has bracteoles almost as long as the primary phyllaries, conspicuous rays, and has been collected at Thunder Bay, Ontario, and thus could be found in Michigan.
This is a very cold tolerant species, and in sheltered areas by buildings in southern Michigan, it may bloom virtually year-round.