Heuchera hispida Pursh var. hirsuticaulis Wheelock, Bull. Torrey Bot. Club 17: 199. 1890; H. americana var. interior Rosendahl, Butters & Lakela; H. hirsuticaulis (Wheelock) Rydberg

Petioles densely long stipitate-glandular. Flowers: hypanthium free 1.1-2 mm, campanulate; petals greenish, white, or pink, narrower than sepals, margins nearly entire or finely dentate. 2n = 14.

Flowering Apr-Jun. Rich woods or open grasslands often over base-saturated granite and gneiss, or in shallow rocky soil; 200-400 m; Ark., Ill., Ind., Mich., Mo., Okla.

Variety hirsuticaulis occurs in a band from Oklahoma to Michigan, where var. americana and Heuchera richardsonii overlap; it is intermediate between those taxa in floral characters but is densely long stipitate-glandular like H. richardsonii. It is probably the result of introgression from H. richardsonii from as long ago as the Pleistocene migrations. Data from a breeding study involving the two species showed a tendency for the shorter hypanthium of var. americana to dominate in the artificial hybrids between H. americana and H. richardsonii (E. F. Wells 1979).