100 THE EVOLUTION OF OUR NATIVE FRUITS 



large and elongated; berries usually not falling singly, but tend- 

 ing to shrivel and hang on the stem; seeds pyriform. 



A. Green-leaved grapes, mostly marked at maturity by absence 

 of prominent white, rusty, or blue tomentum or scurf or con- 

 spicuous bloom on the leaves beneath (under surface some- 

 times thinly pubescent, or minute patches of floccose wool in 

 the axils of the veins, or perhaps even cobwebby); the foli- 

 age mostly thin: tendrils intermittent, i. e., every third joint 

 bearing no tendrils (or inflorescence). V. cinerea and V. 

 Arizonica are partial exceptions, and might be looked for 

 in A A. 



B. Vulpina-like grapes, characterized by thin light or bright 

 green mostly glossy leaves (which are generally glabrous 

 below at maturity except, perhaps, in the axils of the veins, 

 and in V. Champini), with a long or at least a prominent 

 point, and usually long and large, sharp teeth, or the edges 

 even jagged. 



c. Leaves broader than long, with truncate -oblique base ( V. 



Treleasei might be sought here). 



Vitis rupestris, Scheele. (Sand, Sugar, Rock, Bush, or Mountain 

 Grape.) Shrub 2 to 6 feet high, or sometimes slightly climb- 

 ing, the tendrils few or even none, diaphragms plane and 

 rather thin: leaves reniform to reniform-ovate (about 3 to 4 

 inches wide and two-thirds as high), rather thick, smooth 

 and glabrous on both surfaces at maturity, marked by a char- 

 acteristic light glaucescent tint, the sides turned up so as to 

 expose much of the under surface, the base only rarely cut 

 into a well marked sinus, the margins very coarsely angle- 

 toothed, the boldly rounded top bearing a short, abrupt point, 

 and sometimes two lateral teeth enlarged and suggesting lobes : 

 stamens in fertile flowers recurved laterally or rarely ascend- 

 ing, those in the sterile flowers ascending: cluster small, 

 slender, open and branched: berries small (%- to %-inch in 

 diameter), purple-black and somewhat glaucous, pleasant- 

 tasted, ripe in late summer; seeds small and broad. Sandy 

 banks, low hills and mountains, District of Columbia and 

 S. Pennsylvania to Tennessee, Missouri, and S. W. Texas. 

 One or two varieties in cultivation, and it hybridizes freely. 

 Promising for the experimenter. 



