Aralia californica,. Ginseng family, Araliaceae.

Aka Elk Clover (it's not a clover) or California Aralia.

This is a large perennial shrub that grows up to nine feet and then dies back.
It has thick, fleshy (not woody) stems and ball-like umbels of white flowers
in branching racemes; serrated leaves can reach three feet in length. This one
was found growing in deep shade along a seasonal creek at Picchetti Ranch.

This plant can be substituted in herbal preparations for American or Japanese Spikenard.