Introgressive hybridization in two southern California species of Rhus (Anacardiaceae) David A. Young OriginalPaper Pages: 241 - 255
Rocky Mountain species of Paronychia (Caryophyllaceae): A morphological, cytological, and chemical study Ronald L. Hartman OriginalPaper Pages: 256 - 263
Three new legume species from South America Howard S. IrwinMary T. Kalin Arroyo OriginalPaper Pages: 264 - 270
A new Peruvian species of chiropterophilous Couepia (Chrysobalanaceae) Ghillean T. Prance OriginalPaper Pages: 302 - 304
A new Lewisia (Portulacaceae) from the Sierra Nevada of California L. R. HeckardG. L. Stebbins OriginalPaper Pages: 305 - 308
Three new species from the Great Basin Noel H. HolmgrenArthur H. Holmgren OriginalPaper Pages: 309 - 315
The use of neutron activation analysis in pollination ecology Martha M. GaudreauJames W. Hardin Research Notes Pages: 316 - 320