introduced into France at about the same
time as Vulpina, and the French vineyardists selected the most
vigorous and healthy forms for grafting stock. These pass under the
various names of Rupestris Mission, Rupestris du Lot, Rupestris
Ganzin, Rupestris Martin, Rupestris St. George and others. In France,
these varieties have given particularly good results on bare, rocky
soils with hot, dry exposures. In California, Rupestris does not
flourish in dry locations, and as it suckers profusely and does not
take the graft as readily as Vulpina and AEstivalis, it is not largely
propagated.

The clusters of fruit are small, with berries about the size of a
currant and varying from sweet to sour. The berry is characterized by
much pigment under the skin. The fruit has a sprightly taste wholly
free from any disagreeable foxiness. Rupestris under cultivation is
said to be very resistant to rot and mildew of the foliage. The vine
is considered hardy in the Southwest. The attention of hybridizers was
attracted to this species over thirty years ago, and various hybrids
have been produced of great promise for grape-breeding. The root
system of Rupestris is peculiar in that the roots penetrate at once
deeply into the ground instead of extending laterally as in other
species. Like those of Vulpina, the roots are slender, hard and
resistant to phylloxera. The species is easily propagated by cuttings.
The vines bench-graft readily but are difficult to handle in field
grafting.

4. _Vitis vulpina_, Linn. (_V. riparia_, Michx.). Winter Grape. River
Grape. Riverside Grape. Riverbank Grape. Sweet-scented Grape.

Vine very vigorous, climbing. Shoots cylindrical or angled,
usually smooth, slender; diaphragms thin; tendrils intermittent,
slender, usually bifid. Leaves with large stipules; leaf-blade
large, thin, entire, three- or lower ones often five-lobed;
sinuses shallow, angular; petiolar sinus broad, usually shallow;
margin with incised, sharply serrate teeth of variable size; light
green, glabrous above, glabrous but sometimes pubescent on ribs
and veins below. Cluster small, compact, shouldered; peduncle
short. Berries small, black with a heavy blue bloom. Seeds two to
four, small, notched, short, plump, with very short beak; chalaza
narrowly oval, depressed, indistinct; raphe usually a groove,
sometimes distinct. Very variable in flavor and time of ripening.

Vulpina is the most widel