Paddo rockcress is tufted perennial wildflower with several simple (or occasionally branched) stems which are spreading to mostly erect, rising 5-20 cm high. Many short, sterile leafy shoots may also be seen. Plants are largely glabrous but may also be densely covered with much-branched hairs. The basal leaves are found in a basal rosette. They are oblanceolate to oblanceolate-obovate in shape tapering to short petioles. The leaves are 1.5-2.5 cm long and 3-5 mm wide and have entire to occasionally few-toothed margins. The blades are covered with dense, gray, felt-like hairs which are much-branched in a treelike pattern. The stem leaves are oblong to lanceolate, sessile with heart-shaped bases, and 0.5-2 cm long. The herbage of the leaves varies from glabrous to covered with minute, felt-like hairs.
The inflorescence is a 3-10 flowered raceme. The pedicels measure 2-6 mm long and the glabrous to softly haired, purple sepals are 2.5-3.5 mm long. The rose-purple petals measure 4.5-7 mm long. The pedicels are short and glabrous. The fruits are glabrous siliques which are ascending to spreading. The siliques are often turned to one side and measure 3.5-6 cm long and 1.5-3.5 mm wide. The pods vary from straight to slightly arched.
Habitat:
Lemmon's rockcress may be found from British Columbia south through the Cascade and Olympic Mts. to California and east in the mountains to Montana and Colorado.