[Alumroots: The Genus Heuchera in the Columbia River Gorge of Oregon and Washington]

Currant-leaf Alumroot, Gooseberryleaf Alumroot, Thin-leaved Alumroot

Heuchera grossulariifolia var. tenuifolia

Synonym: Heuchera tenuifolia

Thin-leaved alumroot growing on a rock outcrop in the Klickitat State Wildlife Area of south-central Washington.........May 27, 2009.

Characteristics:

Currant-leaf alumroot is an attractive perennial with erect, leafless flower stems from 15-65 cm tall arising from a mass of basal leaves. The herbage varies from minutely haired and glandular to glandular with longer, stiff hairs, or even smooth-surfaced near the base. The leaves are long petioled with the blade orbicular or kidney-shaped with heart-like bases and the blade 1-7 cm wide. The margins are 5- to 7- lobed for 1/5-1/3 of the length. The lobes occasionally overlap, and they are 2-3 times coarsely toothed.

The inflorescence is a panicle, tightly congested at flowering and 1-6 cm long, elongating to 5-12 cm in fruit. The side branches of the inflorescence are up to 1.5 cm long and 2-6 flowered. At flowering, the greenish calyx is tubular, bell-shaped and 4-6 mm long. The 5 lobes or sepals are oval or oblong with the white petals between them. The petals are narrow, oblanceolate to spatulate in shape, and either considerably shorter than the sepals to about 50% longer than the sepals. The ovary is about 3/4 inferior, and the stamens are shorter than the sepals and incurved.

Varieties of Heuchera grossulariifolia:

Var. grossulariifolia: Plants with smaller leaves, from 1-2.5 cm wide. The petals are up to 50% longer than the sepals. The calyx is 4-5 mm long and more bell-shaped (wider than variety tenuifolia). The flowering stems are rarely over 45 cm in height. It is found from Wallowa and Baker counties, OR east through the Snake River Canyon from Payette to Idaho Counties, ID, and through Lemhi, Custer, Blaine, Elmore, Boise, and Baker counties in central Idaho to Ravalli, Beaverhead, Deerlodge, and Madison counties in southwestern Montana.

Var. tenuifolia: Larger plants than the above variety. It has larger leaves, from 3-7 cm wide. The petals are usually shorter than the sepals and the calyx is 5-6.5 mm long and narrower than variety grossulariifolia. It is found in the Columbia River Gorge of Oregon and Washington and in the Payette and Salmon River drainages of Elmore and Boise counties, and in Valley and Idaho counties of Idaho.

Habitat:

Currant-leaf alumroot may be found on grassy hillsides, shaded cliffs and talus slopes, and on alpine scree.

Range:

Curant-leaf alumroot may be found from the Columbia River Gorge of Oregon and Washington east to the Wallowa Mts. of northeastern Oregon and further east through central Idaho to southwestern Montana.

In the Columbia River Gorge, it (variety tenuifolia) may be found between the elevations of 100'-1900' from near Hood River, OR east to near Horsethief Butte.

Close-ups of the leaves and flowers of thin-leaved alumroot. Note the tiny, elliptical shaped petals on the flowers, a good way to identify this species from the similar lava alumroot (Heuchera cylindrica). The photo at lower right is from the webmaster's rock garden in Gresham, OR while the other three photos were taken in the Klickitat State Wildlife Area of south-central Washington.........May 27, 2009.

Thin-leaved alumroot growing in a vertical rock crevice in the Klickitat State Wildlife Area of south-central Washington..........May 27, 2009 plus a close-up of the inflorescence from the webmaster's rockgarden in Gresham, OR. Note the numerous gland-tipped hairs within the inflorescence.

Two photos of the habitat of thin-leaved alumroot as seen in Klickitat County, WA...........May 8, 2010. This species is typically found in this region growing in crevices in near vertical rock walls, but is often found in gravels or talus at the base of cliffs as well as shallow, rocky slopes on steep hillsides.

Thin-leaved alumroot beginning to bloom at left on a basalt outcrop in the Klickitat Wildlife Area...........May 1, 2014. The imgage at right shows the leaves of thin-leaved alumroot on a moist basalt cut bank along the Klickitat River, Klickitat Wildlife Area.....March 24, 2024.

Paul Slichter