52 



PUBLIC HEAUTH BULLETIN NO. 286 



26. Leaves toothed _ 27. 



26. Leaves not toothed (entire) 28. 



27. Plant small, less than 4 dm. tall; flowers yellow (fig. 24). Caltha, p. 118. 

 27. Plant large, over 5 dm. tall; flowers large, white, Hibiscus, p. 122. 

 pink, or purplish (fig, 25). 



xyj 



Figure 24. 



Figure 25. 



28. Leaves mostly basal, heart-shaped; flowers Pontederia, p. 107. 



purple (fig. 26). 

 28. Leaves well distributed along stem; flowers 29. 

 not purple. 

 29. Sheaths (ocreae) around stem above each point of Polygonum, p. 1 14. 

 leaf -attachment; flowers white to red, not fragrant 

 (fig. 27). 

 29. Stems with no sheaths; flowers white, fragrant (fig. 28) _ Saururus, p. 112. 



Figure 26. 



Figure 27. 



Figure 28. 



