1. Suggested phylogeny of prunus serotina and other wide-ranging phylads in North America

   • Rogers McVaugh

   OriginalPaper Pages: 317 - 346

2. Dynamics of leaf variation in the sugar maples

   • Yves Desmarais

   OriginalPaper Pages: 347 - 387

3. Plant explorations of G. Wilson-Browne, S. J., in British Guiana. I. Kanuku mountains

   • Richard S. Cowan and Collaborators

   OriginalPaper Pages: 389 - 414

4. A revision of the genus Bromus, section Bromposis of North America

   • H. Keith Wagnon

   OriginalPaper Pages: 415 - 480