Heuchera americana var. hirsuticaulis

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).

Perennial herb 40 cm - 1.4 m tall Leaves: basal, with a long and stiff-haired stalk. The blade is green and often white-mottled, 0.4 - 1.5 cm long, deeply heart-shaped to nearly rounded or five-sided, with five to nine rounded or blunt lobes, toothed, hairless to variously hairy. Flowers: borne on loose branches of a narrow inflorescence (panicle), each flower 3 - 7 mm long, with the sepals fused into an unequal-sided tube with five lobes. The five narrow petals are greenish to white or pink and sometimes have small teeth, the style and five stamens project far past the sepal tube, and the ovary is single-chambered. Fruit: a two-beaked capsule, 5 - 7 mm long, egg-shaped, opening between beaks, containing spiny seeds that are elliptic but with one straight edge. Flowering stem: leafless but with a few small scale-like bracts, stiff-haired.

Similar species: The typical variety of Heuchera americana differs by having an equal-sided to slightly unequal-sided sepal tube and hairless to slightly hairy leafstalks.

Flowering: April to June

Habitat and ecology: Rare, usually growing along shaded banks and ravines in the eastern part of the Chicago Region.

Occurence in the Chicago region: native

Etymology: Heuchera is named after German botanist Johann Heinrich von Heucher (1677 - 1747). Americana means "from America." Hirsuticaulis means "with hirsuite (stiff-haired) stems."

Author: The Morton Arboretum