Moist ground of shores (sandy, gravelly, rocky), swamps (cedar, black ash), depressions in forests, stream and river banks, ponds, fens; more weedy than most other species of Bidens, in wet disturbed sites, clearings, trails, alleys, barnyards, moist fields, and railroad embankments.

In f. anomala (Fernald) Fernald, the awns are antrorsely barbed (Emmet Co., Drummond Is.). Depauperate plants may resemble B. discoidea, but differ in the awns and at least sparsely ciliate phyllaries.