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PUBLIC HEALTH BULLETIN NO, 286 



31. Small trees or shrubs; flowers not white or showy and 32. 



appearing in early spring. 



31. Shrubs; flowers white in showy racemes, appearing 34. 

 usually in late spring or summer. 



32. Leaves over 4 times as long as broad (fig. 31). _ Salix, p. 112. 



32. Leaves scarcely over 2 times as long as broad.. 33. 



33. Buds covered with overlapping scales; fruit warty Planera, p. 113, 



(fig. 32). 



33. Buds with a single scale; fruit cone-like (fig. 33) AInus, p. 113. 



XI 



Figure 31. 



FiGUEE 32. 



Figure 33. 



