Pennsylvania, a state of diverse geography and geology, is rich in flora. The second edition of The Plants of Pennsylvania identifies the nearly 3,400 species of trees, wildflowers, ferns, grasses, sedges, aquatic plants, and weeds native to or naturalized in the Commonwealth.

Retaining the clearly written identification keys and descriptions that made the first edition such an essential reference, this new edition has been reorganized to reflect recent advances in our understanding of plant relationships. Families and genera are listed in a sequence determined by current...