32 



AMERICAN MEDICINAL BARKS. 



ing one to two shining black seeds, are roundish, or somewhat oval and greenish 



red, wrinkled and pitted, and have a 

 lemon odor. The leaves and flowers 

 are also aromatic. 



The southern prickly ash {Xanthox- 

 ylum clava-herculis), although gener- 

 ally a taller tree than the northern, 

 does not attain great height, not ex- 

 ceeding 45 feet, and sometimes it is 

 only a shrub. The trunk is covered 

 with a slate-gray bark, and the entire 

 tree is furnished with sharp spines, or 

 prickles, those of the trunk smaller 

 and borne on broad corky excrescences 

 which remain after the spines have 

 fallen away (fig. 26), while those 

 of the branches and leaf stems are 

 larger, but also have a broad base 

 (fig. 27). 



The leaves consist of 5 to 17 ovate 

 lance-shaped leaflets 1^ to 3 inches 

 long, with pointed apex and uneven 

 sides, smooth and shining on the upper 

 surface, dull beneath, and margins 

 wavy toothed (fig. 27). After the 

 leaves are out — about June — the nu- 

 merous small greenish white flowers 

 appear, borne in large clusters at the 

 ends of the branches, and not in axil- 

 lary clusters like those of the northern prickly ash. The seed capsules are 



roundish-obovoid, wrinkled, and contain 



roundish-oblong, black, and coarsely 



wrinkled seeds (fig. 27). 



Description of bark. — The dried bark 



of both of these species is official in 



the United States Pharmacopoeia under 



the general name Xanthoxylum. That 



of the northern prickly ash occurs in 



commerce in small curved or quilled 



pieces about 2 inches in length and 



sometimes nearly one-eighth of an inch 



thick, with a brownish gray, corky out- 

 side layer showing whitish patches and 



small black dots, slightly wrinkled, and 



a few shining, brown, straight spines, 



or prickles, about one-fourth of an inch 



in length and with a base about three- 

 fourths of an inch long. The inner 



surface of northern prickly ash bark 



is smooth, whitish, or yellowish. It 



breaks with a short fracture, showing 



the green outer layer and the yellowish 



inner layer. The taste is very pungent and somewhat bitter, but there is no odor 

 139 



Fig. 2G. — Southern prickly ash (Xanthoxylum 

 clava-herculis), trunk. 



Fig. 27. — Southern prickly ash (Xanthoxylum 

 clava-herculis), leaves, fruits, and branch- 

 let showing prickles. 



