532 BOTANY AND PHARMACOGNOSY. 



root-scars and adhering roots, which frequently perforate the 

 bark ; inner surface light brown, longitudinally striate, somewhat 

 porous, occasionally with small pieces of yellow wood adhering; 

 fracture short, with silky, projecting, modified bast fibers, cork 

 light brown, inner and middle bark somewhat tangentially striate 

 and with irregular, dark brown bast areas ; odor faint ; taste bitter; 

 acrid. 



The stem bark occurs in very long, fibrous strips with a gray- 

 ish-black cork and should be rejected. 



Constituents. — Euonymin, a crystalline bitter glucoside 2.16 

 per cent., which resembles digitalin in its physiological action; 

 volatile oil about 1.3 per cent. ; a yellow and brown resin; dulcitol 

 (isomeric with mannitol) ; euonic, malic, citric and tartaric acids; 

 starch; and calcium oxalate. 



Allied Plants. — E. europaus and other species of Euonymus 

 are also used in medicine, and probably contain the same con- 

 stituents. 



VIBURNUM OPULUS.— CRAMP BARK.— The dried bark 

 of the stem and branches of Viburnum Opulus (Fam. Caprifoli- 

 acese), a shrub (Fig. 179, C) indigenous to the Northern United 

 States and Southern Canada, and also found growing in Europe 

 and Asia (p. 382). 



Description. — In transversely curved pieces, 6 to 20 cm. 

 long, I to 2 crh. in diameter, 0.5 to 1.5 mm. thick; outer surface 

 light brown or brownish-black, longitudinally wrinkled, periderm; 

 sometimes exfoliated, revealing a nearly smooth reddish-brown 

 surface, with numerous grayish patches of foliaceous lichens, and 

 small brownish-black apothecia and large brownish lenticels ; inner 

 surface light or reddish-brown, finely striate longitudinally, frac- 

 ture uneven, fibrous, surface light or reddish-brown, with groups 

 of stone cells and bast fibers ; odor slight ; taste astringent, bitter. 



Constituents. — The constituents resemble those of Vibur- 

 num prunifolium. , 

 .XANTHOXYLUM.— PRICKLY ASH BARK.— The dried 

 bark of Xanthoxylum americminm and Fagara (Xanthoxylum) 

 Clava-Herculis (Fam. Rutacese). X. americanum is a shrub or 

 small tree (p. 304) indigenous from Quebec to Virginia and west, 

 to South Dakota, Nebraska and Kansas, and yields Northerij 



