This is a widespread southeastern annual of bare, dry infertile soils. Some western colls. have been misidentified as the more southern species C. michauxii G.L. Webster (= Crotonopsis linearis Michx.). That species has been reported north to se. Mo, s. Ill., Ky. and Va. (F, St, M, J), but revision is needed; it has not been verified from Ky., Va. or N.C. (W). C. michauxii differs in its less branched habit (branches monopodial versus dichotomous or trichotomous); the stellate hairs on upper leaf surfaces have relatively short, non-overlapping arms up to 0.3 mm long (versus overlapping, up to 1 mm); scales on fruits have a minute central axis with long, often ascending arms (versus broad central disk with short appressed arms).