Heuchera americana var. hirsuticaulis

(Wheelock) Rosendahl

Minnesota Stud. Pl. Sci. 2: 60. 1936,.

Endemic
Basionym: Heuchera hispida var. hirsuticaulis Wheelock Bull. Torrey Bot. Club 17: 199. 1890
Synonyms: Heuchera americana var. interior Rosendahl, Butters & Lakela Heuchera hirsuticaulis
Treatment appears in FNA Volume 8. Treatment on page 95. Mentioned on page 94, 96.

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.


Phenology: Flowering Apr–Jun.
Habitat: Rich woods or open grasslands often over base-saturated granite and gneiss, or in shallow rocky soil
Elevation: 200-400 m

Distribution

V8 183-distribution-map.gif

Ark., Ill., Ind., Mich., Mo., Okla.

Discussion

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).

Selected References

None.

Lower Taxa

None.
Elizabeth Fortson Wells +  and Barbara Greene Shipes +
(Wheelock) Rosendahl +
Heuchera hispida var. hirsuticaulis +
Ark. +, Ill. +, Ind. +, Mich. +, Mo. +  and Okla. +
200-400 m +
Rich woods or open grasslands often over base-saturated granite and gneiss, or in shallow rocky soil +
Flowering Apr–Jun. +
Minnesota Stud. Pl. Sci. +
Heuchera americana var. interior +  and Heuchera hirsuticaulis +
Heuchera americana var. hirsuticaulis +
Heuchera americana +
variety +