1. A genetic approach to the taxonomy of Mentzelia lindleyi and M. crocea (Loasaceae)

   • Henry J. Thompson

   OriginalPaper Pages: 81 - 93

2. Chromosome numbers and phylogeny of Trichostema

   • Harlan Lewis

   OriginalPaper Pages: 93 - 97

3. A new Agave from Oaxaca, Mexico

   • Howard Scott Gentry

   OriginalPaper Pages: 98 - 100

4. Introgression in Artocarpus (Moraceae) in Micronesia

   • F. R. Fosberg

   OriginalPaper Pages: 101 - 113

5. Correction

   • Peter H. Raven
   • Harlan Lewis

   Erratum Pages: 113 - 113

6. Petalostemon candidum and P. occidentale (Leguminosae)

   • Duane Isely
   • S. L. Welsh

   OriginalPaper Pages: 114 - 118

7. Studies on Lactarius—I the North American species of sect. Lactarius

   • L. K. Hesler
   • Alexander H. Smith

   OriginalPaper Pages: 119 - 139

8. Supplementary notes on American Labiatae-VII

   • Carl Epling

   OriginalPaper Pages: 140 - 150

9. Additional members American Society of Plant Taxonomists

   Announcement Pages: 150 - 151

10. Notes

    Announcement Pages: xxiv - xxiv