A reappraisal is presented of the taxonomy of three of the four alternate-leaved species ofChrysospleniumoccurring in North America, namelyC. tetrandrum, C. iowense, andC. Rosendahlii, the latter a new species described for the first time. The investigation demonstrates that the species can be readily separated morphologically even as seedlings. Each morphological entity is characterized by a different chromosome number,C. tetrandrum2n = 24,C. Rosendahlii2n = 96.C. iowense2n = c.120, and a distinctive geographical distribution.C. iowense, which has on occasions been regarded as identical withC. alternifoliumvar.sibiricum, is retained as a species in the absence of a modern taxonomic analysis of the Old World speciesC. alternifolium.