American botanist, professor of botany at the University of Texas, Austin. Born in San Antonio, Texas, Marshall Conring Johnston made his first botanical explorations to Mexico, between 1945 and 1947, when he was still in high school. Since then he has collected in most states of northern Mexico: Tamaulipas, Nuevo León, Coahuila, Durango, Zacatecas, and Chihuahua. The bulk of his Mexican collections were made from 1972 to 1974 in connection with Chihuahua Desert Flora. He has also prepared treatments for the Flora of Texas, the Flora of North America and, most recently, Flora Neotropica. His other major publications are the Manual of the Vascular Plants of Texas (with D.S. Correll, 1970) and The Useful Wild Plants of Texas, the Southeastern and Southwestern United States, the Southern Plains and Northern Mexico (with Scooter Cheatham and Lynn Marshall, 1995). The genus Marshalljohnstonia Henrickson in the Asteraceae is named after him.