534 BOTANY AND PHARMACOGNOSY. 



Constituents. — Two resins, one acrid, the other crystalline 

 and bitter ; an acrid volatile oil ; a bitter, alkaloidal principle, some- 

 what resembling berberine; a crystalline phenol compound xan- 

 thoxylin ; ash about 12 per cent. 



Allied Plants. — The fruits of both X. americanuni and 

 Fat^ara Clava-Hcrculis are found in commerce and known as 

 Prickly Ash berries. They consist of 2 to 3 follicles, each of which 

 is 5 to 6 mm. long, brownish-green, dehiscent along the ventral 

 suture and contains one or two sub-globular, somewhat flattened, 

 black, glossy seeds ; odor is aromatic ; taste pungent and bitter. 

 Xanthoxylum fruits contain a volatile oil and resin. 



GRANATUM.— POMEGRANATE BARK.— The dried 

 bark of the root and stem of Punica Granatum (Fam. Punicacese), 

 a shrub (p. 345) indigenous to Northwestern India, and culti- 

 vated in the sub-tropical regions of the Old World. The bark of 

 the root is preferred to that of the stem and by some the drug 

 olDtained from wild plants is also preferred. The bark deterior- 

 ates with age and should not be used after it is a year or two old. 



Stem Bark. — Usually in transversely curved pieces, occa- 

 sionally in single quills, 2 to 8 cm. long, 5 to 20 mm. in diam- 

 eter, bark 0.5 to 2 mm. thick ; outer surface yellowish-brown, with 

 grayish patches of foliaceous lichens, brownish-black apothecia 

 and small lenticels, longitudinally wrinkled ; inner surface light 

 yellow or yellowish-brown, finely striate, smooth ; fracture short, 

 smooth, phelloderm layer dark green, inner bark light brown, 

 somewhat checkered ; odor slight ; taste astringent. 



Root Bark. — Dark brown, with slight longitudinal patches 

 and scales of cork, green phelloderm layer wanting, medullary 

 rays extending nearly to the outer surface. 



Inner Structure. — See Fig. 234. 



Constituents. — Four alkaloids to the extent of i to 3 per 

 cent, in the root bark, but only about half as much in the stem 

 bark. The most important of these alkaloids is pelletierine, the 

 tannate of which is official. Pelletierine (punicine) is a color- 

 less, volatile liquid alkaloid, which readily absorbs oxygen and 

 becomes dark on exposure to air. Its sulphate is Isevorotatory. 

 Isopelletierine (isomeric with pelletierine) is optically inactive 

 and forms an amorphous sulphate. Methylpelletierine some- 



