Coefficient of Conservatism:
Coefficient of Wetness:
A native of Europe first collected in 1880 in Ionia Co., but then not after 1920. No habitats were noted but presumably all were from disturbed ground.
Frequently confused with C. murale, but differs (besides the characters in the key) in rounded margins of the smaller seeds (less than 1.2 mm broad). In C. murale, the seeds are angled on the margin and 1.3–1.5 mm broad.