Columbia Yellow Cress
(Rorippa columbiae )
Photo Copyright 1987 Dean Wm. Taylor
Description: Perennial forb with spreading, dense, short or long hairs; rhizomatous. Stems prostrate to erect, branched, 4 to 15 ¾ inches (1-4 dm) long. Basal and lower cauline leaves generally petioled; middle and upper cauline sessile, ± clasping stem, 1 to 3 inches (2.5–7 cm), oblanceolate to oblong, deeply pinnately lobed. Inflorescence axillary, elongate; flowers with ovate to oblong and hairy sepals, persistent in fruit; petals 3/32 to ⅛ inches (2.5–4 mm), ± tongue-shaped, yellow. Fruit ⅛ to ¼ inch (3–6 mm), widely oblong; hairs dense; pedicels erect to ascending, often appressed
Distribution: Modoc Plateau, Lassen, Modoc, and Siskiyou counties, north to Washington
Habitat: Meadows, playas; vernally wet flats and inundation zones of lake margins and playas. Moist sandy to alkaline soils. 3,900 to 5,900 feet (1,200–1,800 m).
Flowering Period: May to August (September on Modoc Plateau); depends on seasonal moisture
Similar Plants: R. curvisiliqua which is a taprooted annual and has a proportionally narrower and longer fruit.
Status: BLM Sensitive, California Native Plant Society List 1B.2