This occurs on wet acid soils in southeastern states from the Atlantic Coastal Plain to Appalachian regions. Colls. from MCRE and WHIT (KY) are relatively homogeneous, but a few suggest hybridization with gigantea. Colls. from MADI (BEREA), ROWA (KY), WARR (Pr) and WASH (KY) are more varied. Those from ROWA and WARR suggest transitions to glauca. The one from WASH has larger heads, more pubescent and resin-dotted. [There is frequent hybridization among species in this genus, which has uniform chromosome number; 2n = 34 in all reports.]