Scattered in the western North Coast Ranges, southern North Coast, northwestern Modoc Plateau, northern and southern Sierra Nevada foothills, Central Valley, San Francisco Bay region. Throughout California, except deserts and Great Basin. Stem fragments can develop roots under favorable conditions. Seeds disperse with water, mud, human activities, and by clinging to feathers, fur, and feet of animals. Most seeds sink in water.
Seeds typically germinate mid-spring through early summer.
Upon germination, seedlings float to the surface. Seeds under cold dry storage remain highly viable for at least 3 years, but longevity under field conditions is unknown. Seedlings can mature and flower within 8-10 weeks. Seeds lack a dormancy period. Seeds stored in dry soil at room temperature can survive for at least 14 years, but longevity under field conditions is unknown.