VITACE^ 495 



site each, while the third leaf is without a tendril, and so on, 

 there being no tendril or cluster for each third leaf (Fig. 

 209). A tendril or inflorescence terminates the stem growth. 



Flower clusters are borne on growing shoots. In the 

 spring, a bud sends out a growth ; flower clusters appear early 

 near the base of this growth, while the shoot continues to 

 grow until the end of the season. Vitis labrusca averages 

 three to six clusters to a cane; all other species average two 

 to a cane. This shoot bears a number of buds, each of 

 which may, the following season, produce another shoot, in 

 turn bearing fruit clusters. If all these buds are allowed to 

 develop, the fruit developed on the shoots will be very small. 

 Hence in practice it is found necessary, each year, to prune 

 back the current season's growth, leaving only a few buds to 

 develop the succeeding year. 



Grapes are commonly propagated from stem cuttings. 

 The European grape has been grown vegetatively for over 

 5,000 years. 



Leaves. — The grape leaf is simple, palmately lobed or 

 dentate, alternate, with grooved petiole and small stipules. 

 The leaves of the different species vary as to size, shape, 

 number of lobes, nature of petiolar groove, and surface. 



Inflorescence and Flowers. — The grape inflorescence is a 

 compact panicle. As has been indicated, the clusters are 

 borne at the basal nodes of the current season's growth, 

 opposite a leaf or a tendril. In Vitis labrusca, there are from 

 three to six inflorescences to a cane, while in all other species 

 the average is two inflorescences per cane. 



In the wild state, grape vines are of two types : some vines 

 bear self-sterile perfect flowers and other vines bear only 

 staminate flowers. In cultivated forms, there are two types 

 of perfect flowers; those in which the stamens are upright 

 and those in which the stamens are reflexed. In the first 



