This occurs in Appalachian regions mostly at high elevation, and might be expected in the Cumberland Mts. but no coll. has been verified. Records by Linney (1882), RAB and others (M) may all be based on misidentified missouriense, including a coll. from CAMP (EKY, NCU, TENN): E.T. Browne #4258. The species is close to missouriense. It differs (W) in its calyx tube, purplish or purplish-green (versus white); its stamens, 6-8 mm long (versus 9-12 mm); and its spines, usually 0-1 per node (versus 1-3), 3-11 mm long (versus 7-18 mm), and more slender.