This tetraploid (2n = 72) is similar to vulgare, widely scattered in northeastern states and often overlooked (FNA 5, Y, W). In Ky. it has been recorded only after 1960 (M). The name C. glutinosum Nutt. is considered synonymous with pumilum, in part, but its early usage in Ky. (e.g. Short et al. 1833) was probably for nutans (M).