RHIZOMES AND ROOTS. 



231 



PLATE C. 



FIG. 110. Powdered Gentian Root (x 240). 



col, Rounded collenchymatous cells. 



cr, Minute crystals. 



h, Oily globules. 



I, I', Bast in longitudinal and transverse section. 



n, Nucleus. 



pc, p'c', Cortical parenchyma in longitudinal and transverse section. 



pi, pT, Parenchyma of wood. 



rm, Medullary ray. 



s, s', Cork, in surface view and section. 



tr, v, V, Vessels, etc. 



vg, Sieve tubes. 



