Plant Systematics has made a substantial contribution to plant systematics courses at the upper-undergraduate and first year graduate level. This second edition continues to provide the basis for teaching an introduction to the morphology, evolution, and classification of land plants. A foundation of the approach, methods, research goals, evidence, and terminology of plant systematics are presented along with the most recent knowledge of evolutionary relationships of plants and practical information vital to the field. In this second edition, the author includes greatly expanded treatments of families of lycophytes, ferns, gymnosperms, and flowering plants (all with full-color plates), a new chapter on species concepts and the role of systematics in conservation biology, and a new appendix summarizing basic statistical and morphometric techniques used in plant systematics studies. An explanation of maximum likelihood and Bayesian inference algorithms is included in methods of phylogenetic inference, and chapters on morphology and plant nomenclature have been augmented with new material. The second edition of Plant Systematics has been expanded to include: *Fifteen fern families, 9 gymnosperm families, and an increase of angiosperm family treatments from 100 to 129. Each family description includes a plate of full color photographs, illustrating exemplars of the group along with dissected and labeled material to show diagnostic features. * A new chapter on species concepts and the role and impact of plant systematics in conservation biology. * A new appendix on statistical and morphometric techniques in plant systematics. * In addition, the second edition contains more detailed explanations of maximum likelihood and Bayesian phylogeny inference methods, an expanded coverage and glossary of morphological terms, and an updated chapter on botanical nomenclature.