The classification of plants at the infraspecific level poses a number of major problems. In this long-awaited volume, taxonomists in botany, horticulture, agriculture, and forestry explore the limitations of the present system of classification and consider ways to develop more satisfactory and workable systems for the future. The contributors examine such problems as continuous variation, merging populations and counterfeit hybrids, the classification of cultivated plants, and the rigidity of the International Code of Nomenclature.