Coefficient of Conservatism:
Coefficient of Wetness:
A. A. Reznicek
A native of the southeastern United States, spread northward as a noxious weed. Sandy fields, pastures, a weed in disturbed ground and gardens; roadsides and railroads; floodplains and river banks. First collected in Michigan in 1893 in Wayne Co. and soon afterwards in Kent, Muskegon, and St. Joseph Cos.
The fruit is poisonous when eaten by people and farm animals, and the foliage serves as an alternate host for various insects and diseases of crop plants. Occasionally there are a very few spines on a calyx.