During his lifetime Marcus E. Jones was one of the most colorful characters in the American West. An inveterate explorer, first with a team and wagon and later by model-T Ford, he not only covered the West but also Baja California and western mainland Mexico, making his living as a geologist, mining engineer and botanical collector. He was also one of the first to become engaged in the study of the effects of air pollution on plants and animals and served as a witness in many of the early smelter smoke cases. His most lasting contributions however are in the field of botany where he did much to make better known the unique and remarkable flora of western America. Honest, outspoken and controversial he made many enemies in the academic as well as business world. Professor Lenz has here for the first time brought together the facts of his life and career, largely using heretofore unavailable primary sources. Also included is a bibliography of his writings together with a gazetteer of nearly one thousand of Jones's early collecting sites, identified and where possible located on modern maps. During his long life Jones named nearly eight hundred newly discovered plants and these are presented together with the names by which they are known today.--Book Jacket.