Thanks to members of the Native Plant Society, I was told this is a Hydrophyllum tenuipes (Pacific Waterleaf), growing beside a creek on the Sol Duc falls trail. I wish its flower had been in bloom.
Location; Summit County Metro Parks, O'Neil Wood Metro Parks.
Found along foot path.
Habitat: Mature forest.
Hydrophyllum is a genus of flowering plants in the waterleaf family which includes several herbaceous perennials native to North America. They include Hydrophyllum capitatum, the dwarf waterleaf or ballhead waterleaf. Its head is made of a series of five-petaled, five-stamened purple flowers. It was used as a nutritious food source by Native American peoples.