Polypodium californicum

A creeping perennial fern that grows in moist rock crevices. Almost always associated with seeps in the coastal areas and in the middle Sierras. Usually in part-shade, sometimes in the fairly deep shade of bays (Umbellularia californica). It does occur in the shade of many of the oaks, particularly the live oaks. Soils can be heavy clay, gravel or just rock. Polypodiums just need wet feet in winter and early spring, as the ground dries out, so do they, gradually going dormant in mid-summer.