Typical eupatoroides has a broad southeastern range, while var. corymbulosa is centered in the Great Plains (FNA 21). Var. corymbulosa has relatively large heads and inflorescences, but may not be clearly distinct in Ky. and other areas of overlap (e.g. Y). Further analysis is needed. In Ky. Brickellia mostly occurs on somewhat base-rich soil, unlike most species of Eupatorium (except altissimum). It is a more western genus in general, distinguished by its alternate (versus opposite) leaves and 10-ribbed cypselas (versus 5-ribbed); 2n = 18 (versus 20 and multiples).