6o6 A TEXT-BOOK OF BOTANY. 



ern United States and Canada and the root, which contains con- 

 siderable tannin and possibly an alkaloid, has been used in medi- 

 cine. The leaves of Sagcretia theezans of x\sia have also been 

 used as a substitute for tea. A number of plants of this family 

 have been substituted for hops in the fermentation industry, as 

 Ceanothus reclinatiis of the West Indies ; Coluhrina fermcnta of 

 Guiana, and Gouania doniingensis of IMartinique and Hayti. 

 Saponin is found in the bark of Gouania tomcntosa of ^Mexico. 

 A crystalline bitter principle, colletin, occurs in the wood of Col- 

 letia spinosa of South America. The bark of Discaria fehrifuga 

 of Brazil has been used as a substitute for cinchona. A number 

 of genera furnish fish poisons, as Zizyphus, Tapura, and Gouania. 

 Gum-lac is formed on the twigs of Zizyphus Jiijuba of Asia as 

 the result of the sting of an insect (Gocciis lacca). 



The fruits of several species of Zizyphus, thorny shrubs found 

 growing in South America, are edible and enter into the French 

 or Spanish confection known as Jujube-paste. 



b. VITACE^ OR GRAPE FAMILY.— The plants of this 

 family are woody climbers or erect shrubs with alternate, petiolate 

 leaves, and small, greenish, regular flowers, the fruit being a 

 berry. 



The most important genus, economically, is Vitis, to which 

 belong the cultivated grapes, the fruits of which furnish raisins, 

 wine and brandy. The grape-vine indigenous to Europe (Vitis 

 z'inifcf'a) is cultivated in all temperate, and sub-tropical countries, 

 and the variety silvcstris which is found distributed in the }vledi- 

 terranean countries as far east as the Caucasus Mountains is sup- 

 posed to have furnished the cultivated wine grape. The Concord 

 and Catawba grapes are cultivated varieties of the northern Fox- 

 or Plum-grape {Vitis Labnisca) indigenous to the Northern 

 United States east of Minnesota. The Delaware grapes are cul- 

 tivated varieties of the frost-grape (V. cordifolia) and the sweet- 

 scented grape {V. vulpina) of the Eastern United States. The 

 pulpy part of the grape contains from 9 to i8 per cent, of grape- 

 sugar and 0.5 to 1.36 per cent, of tartaric acid. In unfavorable 

 seasons the tartaric acid is replaced in part by malic acid. The 

 soil has a marked influence on the quality of grapes, a sandy soil 



