Grex (Latin for "flock" or "herd") refers to a group of hybrids of common parentage, such as Lilium Pink Perfection Group.[83] These concepts contributed a similar clarity to the nomenclature of garden or agricultural plants that Linnaeus had brought to the naming of native plants two centuries earlier.[5] Stearn continued to play an active part in the International Botanical Congresses over many years, where he was remembered for his rhetorical persuasion on nomenclatural matters.[130] He was also a pioneer in the application of computer-aided technology to (numerical taxonomy), as in his work on Columnea (1969).[15][131]