Columbia Rockcress, Few-flowered Rockcress, Hairystem Rockcress, Sicklepod Rockcress, Small-flowered Rockcress

Sicklepod rockcress blooming on scablands at the Bickleton Ridge Unit of the Klickitat Wildlife Area.......April 20, 2018.

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The photo at right shows a close-up of the flowers and pedicels of Arabis sparsiflora var. subvillosa as seen on the east side of Mt. Adams. Note the numerous branched hairs found on the outer surface of the sepals and pedicels.

Sicklepod rockcress is a biennial or short-lived perennial with one to several upright, simple to branched stems arising 40-80 cm from a mass of basal leaves. Plants are densely hairy below with simple to branched, star-shaped hairs. The numerous basal leaves are oblanceolate in shape, 2 to 9 cm in length and 2 to 8 mm wide. The margins are entire to several-toothed and the blades are finely to coarsely haired. The basal leaves narrow to a slender petiole. There are also numerous stem leaves, reduced in size up the stem. The lower leaves are petiolate, but the upper ones become somewhat clasping or auriculate and somewhat glabrous in texture. The stem leaves are linear-lanceolate to oblanceolate in shape, with mostly entire margins.

The inflorescence is a long, loose raceme of many flowers. The 4 petals may be white to deep purple and measure 6-14 mm in length. The pedicels are glabrous to sparsely covered with branched, radiate hairs. The sepals are often purplish, covered with branched, radiate hairs, and measure 4-6 mm long. The seed capsules are siliques, long and thin, somewhat flattened, usually arched in outline, and either ascending to spreading-drooping. The capsules are glabrous and measure from 6-10 cm long and 1.75-2.5 mm wide.

Variety subvillosa typically has longer and coarser and perhaps harsher hairs on the stems. The basal and lower leaves are commonly coarsely few-toothed. The pedicels are more strongly haired, the hairs longer and often stiffer.

var. atrorubens: Petals a deep purple color. Siliques ascend. Basal leaves toothed. Pedicels of the flowers and siliques typically not haired. Found east of the Washington Cascades from Chelan County to Klickitat County in the south.

var. sparsiflora: Petals white, pink, or light purplish, but lighter than variety atrorubens. Basal leaves entire margined. Pedicels of the flowers and siliques usually ascending, smooth, and hairless. Found in the eastern part of the species' range from Idaho to Utah, west to southeast Oregon, and south to northeastern California.

var. subvillosa: Petals white, pink, or light purplish, but lighter than variety atrorubens. Siliques usually spreading to descending. Basal leaves toothed. Pedicels of the flowers and siliques usually noticeably lightly haired and spreading. Found from central Washington south to California along the east base of the Cascade Range, and east to Montana and Wyoming.

Sicklepod rockcress is found in arid, sagebrush and ponderosa pine habitats.

Sicklepod rockcress is found from British Columbia south along the eastern edge of the Cascade Range to California, and eastward to Alberta, and south through Montana, Wyoming and into Utah.

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