, an annual, can be distinguished from some similar species by its spherical stigma, which is held some way above the anthers, rather than being at a similar height. This sun cup is found only in southern California, between San Diego and Los Angeles, and up to 60-70 miles inland.
Leaves are short-stalked at the base, becoming sessile towards the top of the stem. They, and the stems and calyces, have a covering of white hairs, spreading or appressed. Leaf edges are usually entire, sometimes finely toothed. Flowers have a short hypanthium, four sepals about twice as long, and four broad yellow petals, twice as long again. Each petal has a small to large red spot near the base; less often two spots. At the center of the flower are eight stamens, with yellow filaments and yellow anthers, and the yellow pistil. Fruits are four-angled pods, straight or somewhat twisted.