VEGETABLE POWDERS 



445 



Fig. 151. PIPER. Black. 



a. Sclerenchyma with unequally thickened walls. 

 6. Endosperm tissue with starch and resin. 



c. Epidermal cells. 



d. Typical sclerenchyma. 



e. Crystals of piperin. 

 /. Starch granules. 



g. Pericarp parenchyma. 



