The vascular flora of Pennsylvania annotated checklist and atla /s
Ann Fowler Rhoads, William McKinley Klein ; illustrations by Janet E. Klein ; compiled and produced at the Morris Arboretum of the University of Pennsylvania with the assisstance of Alfred E. Schuyler and Carl S. Keener.
- Philadelphia : American Philosophical Society, 1993.
- 636 p. : ill. ; 29 cm.
- Memoirs series ; v. 207. .