This plant most often presents itself as shiny, three-lobed leaves that grow close to the ground. What is that plant? It is unobtrusive yet distinctive. In the spring it sends up a tall spindly stalk, which splits into branches, each topped with a small head of greenish-yellow flowers. It is Sanicula crassicaulis, also known as Pacific blacksnakeroot, Pacific sanicle, or gamble weed.
A similar species, Coast blacksnakeroot is also common in Marin, but it has yellower flowers and some subtle differences in the fruit.