THE GRAPES OF NEW YORK. 



107 



SPECIES OF AMERICAN GRAPES. 

 CON'SPECTUS OF NORTH AMERICAN SPECIES OF VITIS. 



A. Skin of mature berry separating freely from the pulp. 



B. Nodes without diaphragms: tendrils simple 1. 



V. rotundifolia. 

 V. munsoniana. 



B.B. Nod'.-s with diaphragms; tendrils forked. 



C. Leaves and shoots glabrous at maturity and without bloom. 

 Tendrils intermittent (V'. cincrea and V. arizonica are partial 

 exceptions and might be looked for under C.C). 



D. Leaves thin, light, bright green, generally glabrous 

 below at maturity except perhaps in the axils of the 

 veins {V. champini an exception) with a long or at 

 least a prominent point and usually long and sharp 

 teeth or the edge even jagged. (V. bicolor might be 

 looked for here.) 



E. Leaves broader than long; petiolar sinus usu- 

 ally wide and shallow. (V. trelcasci might be 



sought here.) 3. V. rupestris. 



E.E. Leaves ovate in outline; petiolar sinus 

 usually medium to narrow. 



F. Diaphragms thin; young shoots not red. 4. V. monticola. 



5. V. riparia. 



6. V. treleasei. 



7. V. longii. 



8. V. champini, 

 F.F. Diaphragms thick; young shoots 



bright red 9. V. rubra. 



D.D. Leaves thickish, dull colored or grayish green, often 

 holding some close dull pubescence below at maturity, 

 shoots and leaves nearly always more or less pubescent 

 when young; the teeth mostly short; the point mostly 

 rectangular and conspicuous. 



E. Plants strong, climbing, with stout persistent 

 tendrils. 



F. Young shoots cylindrical, glabrous or 



very soon becoming so 10. V. cordifolia. 



F.F. Young shoots angled, covered the 

 first year with tomentum or wool 



13- 



E.E. Plants scarcely climbing, tendrils perishing 



when without support 14- 



D.D.D. Leaves orbicular, scallop shaped; species of the 

 Pacific Coast i5- 



V. baileyana. 

 V. berl&ndieri. 

 V. cinerea. 



V. arizonica. 



V. califomica. 



