Flower in the Backyard

I'm not sure if this flowering plant is native to the Valley. Near the sewage treatment facility the forest undergrowth is lush, like the forest along the Northern California cost...well, not that lush, but very unlike most of the Valley's floor. But this is near the creek, and maybe that's the reason, and not a "things are greener over the septic tank"!! The plant is on the facility.