Camissoniopsis cheiranthifolia (beach suncup or beach evening primrose) is a species of the evening primrose family and is native to open dunes and sandy soils of coastal California and Oregon. The beach suncup grows prostrate along the beach surface, forming mats more than 1 m across. It forms long stems growing from a central crown, lined with silvery grey-green leaves. The prostrate form and swinging stems allow the plant to survive well on the windy, shifting sands of the coast. The four-petalled flowers open in the morning (typical among suncups) and are bright yellow, fading to reddish.