18 PUBLIC HEALTH BULLETIN NO. 286 



13. Leaves simple 17. 



13. Leaves compound 14. 



14. Trees 16. 



14. Shrubs _. 15. 



15. Plant thorny; leaflets not over 9 usually 7 or 5 (fig 13) - Rosa, p. 1 19. 

 15. Plant not thorny; leaflets more than 11 (fig. 14) Amorpha, p. 120. 



xVs 



Figure 13. 



Figure 14. 



16. Leaflets many and small, usually 12-22; tree Gleditsia, p. 120. 



prominently thorny (fig. 15). 

 16. Leaflets fewer and large, usually 9; tree not Carya, p. 112. 



thorny (fig. 16). 



Figure 15. 



Figure 16. 



17. Leaves aromatic when crushed 18. 



1 7. Leaves not aromatic when crushed 22. 



18. Leaves with small, orange wax glands on Myrica, p. 112. 



lower surface when examined with lens; 



leaves usually prominently toothed (fig. 17). 

 18. Leaves without wax glands below; leaves 19. 



entire or nearly so. 



