An illustrated flora of the northern United States, Canada and the British possessions : from Newfoundland to the parallel of the southern boundary of Virginia, and from the Atlantic Ocean westward to the 102d meridian - Britton, Nathaniel Lord, 1859 -1934 (C. Scribner's sons, 1913)

An illustrated flora of the Pacific States: Washington, Oregon, and California - Abrams, Le Roy, 1874 -1956 (Stanford University Press, 1923)

An illustrated flora of the Pacific States: Washington, Oregon, and California - Abrams, Le Roy, 1874 -1956 (Stanford University Press, 1944)

An illustrated flora of the Pacific States: Washington, Oregon, and California - Abrams, Le Roy, 1874 -1956 (Stanford University Press, 1960)

An illustrated guide to the special status plants of the Shoshone Resource Area (Upper Snake River District) - United States. Bureau of Land Management. (Bureau of Land Management, Idaho State Office, 1998)

Illustrated manual of proposed endangered and threatened plants of Utah - U.S. Fish; Wildlife Service (Denver, Colorado, 1979)

Immatures of exomalopsine bees with notes on nesting biology and a tribal key to mature larvae of noncorbiculate, nonparasitic Apinae (Hymenoptera, Apidae) - Rozen, Jerome G. Jr. (Jerome George), 1928 - (American Museum of Natural History, 2011)

Important western browse plants - Dayton, William A. (William Adams), 1885 - (U.S. Dept. of Agriculture, 1931)

Index herbariorum - International Association for Plant Taxonomy (Published and Distributed for International Association for Plant Taxonomy by New York Botanical Gardens, 1990)