LICORICE 



313 



pith composed of somewhat polyhedral parenchyma, containing 

 numerous starch grains, or prisms of calcium oxalate. In roots the 

 pith is wanting. 



Powder. Light brownish-yellow ; starch grains numerous, mostly 

 single and ellipsoidal or ovoid, and from 0.002 to 0.020 mm. in diam- 



FIG. 140. Longitudinal-transverse section of licorice rhizome including the cam- 

 bium: P, parenchyma; T, tracheae or vessels; WF, wood fibers; C, cam- 

 bium; S, sieve; CF, crystal fibers; BF, bast fibers; MR, medullary ray. 



eter; tracheae mostly with bordered pores; wood and bast fibers 

 numerous, strongly lignified, very long, much attenuated' at the ends, 

 and about 0.010 mm. in width; crystal fibers with monoclinic prisms 

 of calcium oxalate, the latter from 0.010 to 0.020 mm. in diameter; 

 occasional fragments of reddish-brown cork cells. 



