These plants began to evolve ~50 million years ago when the Rockies were formed. They adapted to arid conditions in the rain shadows of the Rocky (and other) Mountains, and were able to move in as the others moved out or up.
Examples: manzanitas, bird's foot fern, snapdragons, locoweed, canchalagua, most lotus, sycamore(!), oaks.
Where do these species live at the Santa Rosa Plateau now?
Comments and feedback: Tom Chester
Last update: 6 November 2005.