Unknown plant

I've been trying to identify this plant at Huckleberry Regional Botanical Preserve for a long time with no success. I hiked with a park naturalist last spring; she didn't know what it was either! Any thoughts?

It's the slow time in northern California ecosystems. It's been a long time since it's rained, and we probably won't get any before mid November. Things are slow, birds are hiding... but pay attention and you'll see fine things.