2a. "Tendrils or flower clusters borne on three or more successive nodes"
Vitis labrusca, Northern Fox Grape Native, Piedmont & coastal plain Leaves "densely felted below by persistent rusty or reddish hairs which conceal the surface"
2b. "Tendrils or flower clusters missing opposite every third leaf usually"
Vitis aestivalis var. aestivalis, Summer Grape Native, Piedmont & coastal plain Leaves 3-5lobed, underside with "cobwebby" reddish hairs that don't hide the whitened leaf surface
Vitis vulpina, Winter Grape Native, Piedmont & coastal plain Leaves heart-shaped, unlobed or barely lobed, "glabrous or soon becoming so except in vein axiils"