Wall lettuce is an introduced, annual or biennial herb with milky sap. It has slender, hairless, and leafy stems, 30-100 cm tall, that are green, or commonly, reddish. The leaves are alternate, 6-20 cm long , almost lyrate with pointed lobes, and clasping at the base. The very small (1 cm) heads are narrow, 5-flowered, yellow, and numerous in an open cluster. Wall lettuce grows commonly to abundantly in moist forest openings and edges, and roadsides at low to middle elevations.