Collected as a waif at River Rouge, Detroit (Wayne Co.), by O. A. Farwell in 1912 and along a railroad near East Lansing (Ingham Co.) by E. E. Watson in 1923 (MSC). This rare escape from cultivation is subsp. cucumerifolius (Torr. & A. Gray) Heiser, native much farther south.

The leaves are quite distinctive, with blades less than 8 (–9) cm long, and plants never attain the robust size of which H. annuus is capable.