752 



BOTANY AND PHARMACOGNOSY. 



crystals. /. nigra has also in the medullary rays rosette aggre- 

 gates of calcium oxalate. /. regia appears more nearly to resem- 

 ble /. cinerea. 



107. ARALIA NUDICAULIS (American Sarsaparilla). 

 (Fig. 192.) Light brown; rosette aggregates of calcium oxalate 

 from 35 to 70 /x ; spherical starch grains, from 10 to 15 /u,; 

 tracheae with scalariform and reticulate thickenings, also simple 

 and bordered pores ; wood fibers long, with slightly thickened 

 walls and simple pores ; large oil glands, and brown cork cells. 





h 



Fig. 299. Several forms of sclerenchymatic fibers: A, intermediate fibers from wood 

 of ipecac showing lignified walls with oblique simple pores and one cell containing starch; 

 B, bast fibers from cinchona showing in transverse section a stratification of the wall, 

 and in longitudinal section a striation of the walls; C, longitudinal section of quassia showing 

 tracheids with bordered pores and medullary-ray cells. 



108. STILLINGIA. Light brown ; sclerenchymatous fibers 

 very long, thick-walled and swelling perceptibly in potassium 

 hydrate solution; starch grains spherical or ellipsoidal, 15 to 30 ix, 

 in diameter; secretion cells containing oil. resin and a brown pig- 

 ment ; calcium oxalate crystals rosette-shaped, 35 /x in diameter. 



109. EUONYMUS. Light brown (Fig. 300, E) ; bast fibers 

 long, thin-wallcd, non-lignified, the walls frequently modified to 

 mucilage and possessing numerous small, more or less oblique 

 pores, and irregular ends ; starch grains spherical, 4 to 10 ,u in 



