Thomas Joseph Givnish (born May 14, 1951) is an American botanist, ecologist, and evolutionary biologist, holder of the Henry Allan Gleason Chair in Botany and Environmental Studies at the University of Wisconsin.
[1] He has written extensively on speciation, adaptive radiation, and determinants of diversity in several plant groups, including Bromeliaceae, Rapateaceae, Orchidaceae as well as the Hawaiian lobelioids.
He graduated from Princeton University with a BA in mathematics in 1973 and received his Ph.D. in biology there in 1976.
His doctoral dissertation was entitled Leaf form in relation to environment: A theoretical study.
He has published several studies on the adaptive significance of plant form and physiology, the interface between physiological and community ecology, the ecology and evolution of forest herbs, carnivorous plants, and epiphytes, fire ecology, evolution atop the tepuis of Venezuela, and self-assembly of patterned peatlands in the Florida Everglades.