724 



BOTANY AND PHARMACOGNOSY. 



C. GLANDULAR AND NON-GLANDULAR HAIRS WANTING. 



20. COCA. — Dark green (Fig. 286), calcium oxalate in 

 monoclinic prisms 3 to 10 /* in diameter ; walls of under epidermal 

 cells extended as minute papillae (Fig. 261). 



21. GUAIACUM. — Dark green (p. 669) ; numerous lemon- 

 yellow or dark brown resin masses, which when mounted in 



Fig. 286. Coca leaf: O, hexagonal prisms of calcium oxalate; U, surface view of 

 a cell of the upper epidermis; L, view of fragments of lower epidermis in surface and cross 

 sections, showing elliptical stomata, and cells with circles which represent papillae in 

 surface view; S, sclerenchymatic fibers; M, loose parenchyma. Two fragments with an- 

 nular tracheae are also shown. 



chloral are wine-colored at the margin; few fragments of tissues 

 with characteristic sclerenchymatous cells and fibers ; few crystals 

 of calcium oxalate in monoclinic prisms. 



22. UVA URSI. — Yellowish-green ; calcium oxalate in mono- 

 clinic prisms 7 to 10 /* in diameter, frequently in crystal fibers; 

 non-glandular hairs few, somewhat curved, i -celled, thick-walled, 



