"The Peterson Identification System," describes Roger Tory Peterson's unique system that shows exactly what features to look for to tell one species from another.
Here are descriptions and illustrations of 1,492 species from 77 families - virtually all of the wildflowers found from British Columbia to Baja California, from the Rocky Mountains to the Pacific Ocean. Grouped by colour, each species description includes field marks, size, habitat, range, flowering season, and common and scientific names.
Roger Tory Peterson, one of the world's greatest naturalists, received every major award for ornithology, natural science, and conservation as well as numerous honorary degrees, medals, and citations, including the Presidential Medal of Freedom. The Peterson Identification System has been called the greatest invention since binoculars.