Penstemon rydbergii
Scrophulariaceae (Snapdragon Family)

Per Axel Rydberg , 1860-1931, was a Curator and Field Agent with the New York Botanical Garden, USDA Field Agent, author of Flora of Montana and Yellowstone Park (1900), Flora of Colorado (1906), and Flora of the Rocky Mountains and Adjacent Plains (1917). These books were based in great part on his own collections over many years.  He first collected in Colorado in 1891.

Weber considers Rydberg, Greene, and Nelson the most important figures in Rocky Mountain botany. Rydberg split many genera and wanted each species to be distinct and distinguishable from all others, a lead that Weber has followed.