Horticulture has remained far behind in understanding of botanical principles. Recent phylogenetic (DNA-based) reorganization of higher plants has revolutionized taxonomic treatments of all biological entities, even when morphology does not completely agree with their organization. This book is an example of applying principals of botanical phylogenetic taxonomy to assemble genera, species, and cultivars of 200 vascular plant families of ferns, gymnosperms, and angiosperms that are cultivated for enhancement of human living space; homes, gardens, and parks. The emphases are on cultivated...