Viola pedunculata

Viola pedunculata, the California golden violet, Johnny jump up, or yellow pansy, is a perennial yellow wildflower of the coast and coastal ranges in California and northwestern Baja California. However, the common name "Johnny jump up" is usually associated with Viola tricolor, an introduced garden annual. The plant grows on open, grassy slopes, in chaparral habitats, and in oak woodlands, from sea level to around 3,280 feet (1,000 m). It prefers part shade, but will tolerate sun in many locations....read more on Wikipedia.