322 MANUAL OF AMERICAN GRAPE-GROWING 



that Bourquiniana is a hybrid. The hybrid supposition is 

 corroborated to a degree by the characters being more or less 

 intermediate between the supposed parent species, and also 

 by the fact that up to date no wild form of Bourquiniana has 

 been found. The only northern variety of any importance 

 supposed to have Bourquiniana blood is the Delaware, and in 

 this variety only a fraction of Bourquiniana blood is presum- 

 ably present. Bourquiniana can be propagated from cuttings 

 more easily than the typical ^Estivalis but not so readily as 

 Labrusca, Vulpina or Vinifera. Many of the varieties of Bour- 

 quiniana show a marked susceptibility to mildew and black- 

 rot ; in fact, the whole Herbemont group is much inferior in 

 this respect to the Norton group of ^Estivalis. The roots are 

 somewhat hard, branch rather freely and are quite resistant 

 to phylloxera. 



8. Vitis bicolor, Le Conte. Blue Grape. Northern Summer 

 Grape. Northern ^Estivalis. 



Vine vigorous, climbing ; shoots cylindrical or angled, with long 

 internodes, generally glabrous, usually showing much blue bloom, 

 sometimes spiny at base; diaphragms thick; tendrils intermittent, 

 long, usually bifid. Leaves with short, broad stipules ; leaf-blade 

 large ; roundish-cordate, usually three-, sometimes on older growth 

 shallowly five-lobed, rarely entire ; petiolar sinus variable in depth, 

 usually narrow ; margin irregularly dentate ; teeth acuminate ; gla- 

 brous above, usually glabrous below and showing much blue bloom which 

 sometimes disappears late in the season ; young leaves sometimes 

 pubescent ; petioles very long. Cluster of medium size, compact, 

 simple ; peduncle long. Berries small, black with much bloom, acid 

 but pleasant tasting when ripe. Seeds small, plump, broadly oval, 

 very short beak ; chalaza oval, raised, distinct ; raphe distinct, showing 

 as a cord-like ridge. 



Bicolor is readily distinguished from ^Estivalis by the ab- 

 sence of the reddish pubescence and by blooming slightly later. 

 The habitat of Bicolor is to the north of that of ^Estivalis, oc- 

 cupying the northeastern, whereas ^Estivalis occupies the 



