This is a widespread across much of eastern North America, but it is rare to absent on the southeastern Coastal Plain. It has been treated as a subspecies of the Eurasian C. quadriusulcata (Maxim.) Franch. & Savigny, but some authors have preferred to retain it as a species (Boufford 1983, 2005; W). Recent molecular analysis does support species status (Xie et al. 2009).