Ipomopsis polycladon
Spreading Ipomopsis; Manybranched Ipomopsis

Hitchcock, C. L., A. Cronquist, M. Ownbey, and J. W. Thompson. 1959. Vascular plants of the Pacific Northwest. Part 4. University of Washington Press, Seattle. 510 pp. Illustration by Jeanne Janish. Reprinted with permission of the University of Washington Press.