EXPLANATION OF THE PLATES. 



Plate CCCXXVL Platanus occidentalis. 



1. A flowering branch, natural size. 



2. Diagram of a staminate flower. 



3. Diagram of a pistillate flower. 



4. A head of staminate flowers with most of the flowers 



removed, enlarged. 



5. A staminate flower, enlarged. 



6. A stamen, enlarged. 



7. A pistillate flower, enlarged. 



8. A pistil, enlarged. 



9. Vertical section of an ovary, enlarged. 



10. Portion of a branch and stipule, natural size. 



11. A winter branchlet, natural size. 



12. Portion of a branchlet showing bud and the base of 



a petiole, natural size. 



13. Vertical section of a branchlet, bud and petiole, 



natural size. 



Plate CCCXXVIL Platanus occidentalis. 



1. A fruiting branch, natural size. 



2. Vertical section of a head of fruit, natural size, 



3. An akene, enlarged. 



4. Vertical section of an akene, enlarged. 



5. A seed, enlarged. 



6. An embryo, enlarged. 



