8.
Heuchera americana
Linnaeus, Sp. Pl. 1: 226. 1753.
American alum-root
Herbs
acaulescent; caudex branched.
Flowering stems
leafy, 40-145 cm, glabrous or short stipitate-glandular.
Leaves:
petiole glabrous or very short to long stipitate-glandular; blade (often variegated adaxially), broadly ovate to cordate, shallowly 5-9-lobed, 3.5-11 cm, base cordate to nearly truncate, lobes rounded or ovate, margins dentate, apex acute or obtuse, surfaces abaxially glabrous or short stipitate-glandular, adaxially glabrous or short stipitate-glandular.
Inflorescences
diffuse.
Flowers:
hypanthium weakly bilaterally symmetric, free 0.6-2 mm, green, urceolate or campanulate, abruptly inflated distal to adnation to ovary, 3-7.2 mm, very short stipitate-glandular; sepals erect, green-tipped, equal, 1-2.4 mm, apex rounded; petals erect, greenish, white, pink, or purple, narrowly spatulate, unlobed, 0.9-4 mm, margins entire or finely dentate or fimbriate; stamens exserted 3-5 mm; styles exserted 2.6-6.4 mm, 4-7 mm, to 0.1 mm diam.
Capsules
ovoid, 4-10.5 mm, beaks divergent, not papillose.
Seeds
dark brown, ellipsoid, 0.6-0.9 mm.
Varieties 3 (3 in the flora): e North America.
Heuchera americana
is highly polymorphic and distributed over a large part of the eastern United States and Canada. Its variability is largely the result of its wide geographic range, the sporadic, semi-isolated distribution of populations, and interaction of differential adaptation and genetic drift made possible by its distribution pattern.
Heuchera americana
intergrades with both
H. pubescens
and
H. richardsonii
where they overlap; the intergrading form with
H. pubescens
is
H. americana
var.
hispida
, and with
H. richardsonii
it is
H. americana
var.
hirsuticaulis
. A breeding study between
H. americana, H. pubescens, H. richardsonii
, and other species demonstrated ease of artificial hybridization and fertility of offspring among
H. americana, H. pubescens
, and
H. richardsonii
(E. F. Wells 1979).
Individuals of the three varieties do not form inter-mixed populations; populations tend to be geographically isolated from one another and to be relatively uniform, displaying somewhat narrow character variation within a population.
The Cherokee Indians took
Heuchera americana
for dysentery and used the powdered root for malignant ulcers, bad sores, bowel complaints, piles, female problems, and sore mouth. The Chickasaw Indians used the root as an astringent and tonic (D. E. Moerman 1998).
