VITACEvE 499 



Key to Most Important Species of Vms' 



Skin of mature berry not separating freely from the pulp, Vilis vinijera 



(Old World grape). 

 Skin of mature berry separating readily from the pulp. 



Nodes without diaphragms (Fig. 207, A) ; tendrils forked, Vilis rolundifolia 



(Southern fox grape). 

 Nodes with diaphragms (Fig. 207, B); tendrils forked. 

 Leaves and shoots glabrous at maturity and without bloom. 



Leaves broader -than long; petiolar sinus usually wide and shallow, 



V. rupeslris (sand grape). 

 Leaves ovate in outline; petiolar sinus usually medium to narrow, 

 V. riparia (river bark grape). 

 Leaves rusty or white tomentose or glaucous blue below. 



Leaves not covered with a thick, dense felt-like tomentum when 



fully grown, V. astivalis (summer grape). 

 Leaves covered with a dense, thick, felt-like tomentum when fully 

 grown, V. labrusca (Northern fox grape). 



Vitis vinifera (Old-World Grape, Wine Grape, Raisin 

 Grape). — The Old-World grape is not as large a plant as 

 most American species. The leaves are thin, smooth, and 

 three- to seven-lobed; they may be smooth or woolly-hairy 

 when young; the lobes are rounded or pointed, and their 

 margins coarsely toothed. The oval, oblong, or globular 

 berries are in long and broad clusters. 



The varieties of this species have a high sugar content. 

 On this account, they make better wine and raisins than 

 American varieties. American varieties are table grapes; 

 European varieties are wine and raisin grapes. The latter 

 are now grown in CaHfornia, where the wine and raisin in- 

 dustries have developed to considerable importance. V. 

 vinifera is not resistant to the attacks of Phylloxera, a scale 

 attacking the leaves and roots. American varieties are 

 comparatively more resistant to these insects and on this 

 account are used as stocks upon which European varieties 

 are grafted. 



'The key is adapted from "The Grapes of New York," by Hedricl*. 



