John Ray

His classification of plants in his ''Historia Plantarum'' was an important step towards modern taxonomy. Ray rejected the system of dichotomous division, by which species were classified by repeated sub-division into groups according to a pre-conceived series of characteristics they have or have not, and instead classified plants according to similarities and differences that emerged from observation. He was among the first to attempt a biological definition for the concept of ''species'', as "a group of morphologically similar organisms arising from a common ancestor". Another significant contribution to taxonomy was his division of plants into those with two seedling leaves (dicotyledons) or only one (monocotyledons), a division used in taxonomy today. Provided by Wikipedia
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