Bui. 824, U. S. Dept. of Agriculture. 
PLATE III, 
■Ji 
Mum • 
Fig. I.— Crystals, Disc Floret. (xl96.) Fig. 2.— Tooth, Disc Floret. (xl40.) 
i> S> "-" '■■', .., . 
-'-A 
%^& J$ " 
ggf^M^ 
Fig. 3— Pollen Grain. (X290.) 
Fig. 4— Pollen Grains. (XI40.) 

□ 
o 
Fig. 5.— Achene Tissue and Crystals. 
(X204.) 
Fig. 6.— Crystals from Achene. 
(Magnified.) 
