1 CEPAGES. Ill 



vines planted in France then; the Riparia is used, with 

 good reason, as one of the best grafting- stocks. 



The V. Riparia of all the American species spreads over 

 the largest geograpaical area; it extends from the centre of 

 Canada in the north, which is one of the coldest climates, to 

 Texas and Louisiana in the south of the United States, and 

 on the west to the Rocky Mountains. It is specially abun- 

 dant in the Central States and those bordering the Atlantic. 



In the northern limit of its geographical distribution, the 

 Riparia withstands a cold of 30 C., and in the south resists 

 the highest temperatures. On account of its early growth, its 

 first buds are very subject to spring frosts, but, when frost 

 bitten, large numbers grow on the trunk and base of the 

 spurs; this is not a fault when it is grown for the pro- 

 duction of cuttings, and has no importance when grafted, for 

 we shall see when we study grafting that early budding does 

 not force the graft to grow earlier. 



The Riparia does not succeed in too dry surroundings, espe- 

 cially if little fertile; it has a poor growth in such soils, and 

 the difference in size between the stock and scion, which 

 occurs with all varieties, is then accentuated; we will discuss 

 this further in the chapter on grafting. The Riparia is 

 vigorous in the wild state in moist soils only, and it is especially 

 on the sandy and fresh banks of rivers that it attains its 

 greatest development in America. This applies also in 

 France, where the Riparia grows much better in cool than in 

 dry, sandy soils; but it does not like wampy or wet ground. 



The Riparia grows in soils of very different kinds in the 

 United States, belonging to the primitive formations or their 

 derivatives, and to a less extent in secondary or tertiary for- 

 mations. The recent alluvials, the rich siliceous or red clay 

 siliceous soils (pebbly or not), the fresh and fertile sands, the 

 soils formed of hard calcareous debris, but fresh and rich, 

 are the surroundings in which it acquires a fine development. 

 The Riparis imported into France by Meissner were selected 

 on the banks of the Mississippi River where the soils are 

 formed by clay -sandy alluvials, composed of fine particles, 

 dark-grey colour, and great fertility, resting on hard cal- 

 careous 01 laminated banks of black-blue clay. As an 

 example, one of these very fertile soils contained (physical 

 analysis): 



Clay .. .. .. 65.020 per cent. 



Sand . . . . . . 27 . 500 



Limestone 7 . 273 



