Arthur John Cronquist (1919–1992) was a United States biologist, botanist and a specialist on Compositae. He is considered one of the most influential botanists of the 20th century, largely due to his formulation of the Cronquist system. Two plant genera in the aster family have been named in his honor. These are Cronquistia, a possible synonym of Carphochaete, and Cronquistianthus, which is sometimes included as a group within Eupatorium. The former was applied by R.M.