RHIZOMES AND BOOTS. 



269 



PLATE CXIX, 



FIG. 129. Powdered Valerian Rhizome (x 240). 



a, Starch. 



end, Endodermis. 



ep, Epidermis of root. 



e'f>', Tegumentary tissue of rhizome. 



h, Cells of the hypoderma of root. 



I, I', Collenchymatous bast tissue, in longitudinal and 



transverse section. 

 pc, Cortical parenchyma. 

 per, Pericycle. 

 pm, Parenchyma of pith. 

 pt, Hairs on root. 



sc, Sclerenchymatous cells of rhizome. 

 tr, vp, Vessels, etc. 



