This is a widespread variable northeastern tetraploid, concentrated in cool temperate regions and uncommon in most of Ky. west of the Appalachian Plateau. See also notes under flabellata and iracunda, which have records that are not yet reliably segregated from macrosperma in Ky. Another close relative expected in Ky. is the triploid, C. schuettei Ashe (FNA 9, K, W). Most of the uncertain records mapped here as open dots may be transferred to iracunda. Some records from BOYD and LYON (GH) are based on atypical colls. with suborbicular leaves, which also suggest collina.