VEGETABLE POWDERS 



455 



Fig. 157. PYRETHRUM. Flowers. 



o. Epidermal cells. 



b. Epidermis, lateral view. 



c. Trichomes. 



d. Sclerenchyma. 



e. Pollen grains. 



/. Parenchyma with crystals. 

 g. Tracheids. 



