Coefficient of Conservatism:
Coefficient of Wetness:
Native in eastern North America, and presumably in Michigan, where first collected in 1838 in Cass and Jackson Cos. by the First Survey, but weedy in habit. A pioneer on ground recently bulldozed, cleared, burned, or exposed by lowering of a pond or river; roadsides, railroads, old fields, shores, gravel pits, dump heaps, yards, and other disturbed ground; a weed in gardens.
Solanum ptychanthum has umbelliform inflorescences, seeds 1.3–1.6 mm long, and anthers 1.4–1.9 mm long; the berries are shiny and plants diploid. In the related Eurasian S. nigrum L., not so common in North America, the inflorescence is racemiform, the seeds and anthers are larger; the berries are dull; and plants are hexaploid. The southern S. americanum, as now defined, is similar to S. ptychanthum but has numerous white flecks on the immature fruit and fewer (not over 5) hard granules mixed with the numerous seeds in the mature berries.