Sicklepod Rockcress (Arabis sparsiflora)
Many books/botanists now classify this as Boechera sparsiflora.
The common suffix, cress, seems to be a generic term for some edible members of the mustard family (most definitions refer to a pungent taste). This variety occurs at all elevations, but only east, and south of the Cascades. Arabis is the Greek word for cress, and also the Greek word for Arabia, which may allude to the sandy soils the plant can tolerate. We found it near the top of the Dalles Mountain Road.