3. Vitis labrusca L. (fox grape, Labruscan vineyard grape)

Pl. 581 h, i; Map 2719

Young stems circular in cross-section or slightly angled, densely pubescent with cobwebby hairs at flowering and sometimes also with sparse stiff, spreading, gland-tipped hairs, green, gray, or brown, the nodes not glaucous, not reddish-tinged. Pith interrupted at the nodes, the diaphragms 0.5–1.5 mm wide on new growth, eventually thickening to 1.0–2.5 mm wide on older branches. Older stems with the bark shredding, not appearing warty. Tendrils common, present at most nodes, not regularly grouped at pairs of nodes, 2- or 3-branched. Leaves with the petiole 2/3 as long to about as long as the blades, glabrous or sparsely to moderately hairy at flowering time. Leaf blades mostly 5–25 cm long, slightly shorter than to slightly longer than wide, broadly ovate or nearly circular in outline, flat or slightly convex at maturity, unlobed or shallowly 3-lobed, less commonly deeply 3- or 5-lobed, the sinuses mostly U-shaped, the lobes usually tapered or narrowed to a sharply pointed tip, the upper surface glabrous or sparsely and minutely hairy along the main veins, not shiny. Undersurface of young leaves densely pubescent with light gray to more commonly tan cobwebby hairs that are more or less appressed to the surface, these persistent at maturity and obscuring the surface, the undersurface not glaucous. Inflorescences often at 3 or more adjacent nodes, 6–14 cm long, narrowly to broadly pyramid-shaped or less commonly cylindrical. Fruits mostly 10–25 per infructescence, 12–20 mm in diameter, the surface with lenticels absent, dark reddish purple to black, not or only slightly glaucous. Seeds 5–8 mm long, brown. 2n=38. May–June.

Introduced, uncommon and widely scattered in the state (northeastern U.S. west to Michigan and Tennessee; Canada; escaped from cultivation farther south and west). Fencerows, old fields, roadsides, railroads, and open disturbed areas.

Some botanists prefer to restrict the use of the name V. labrusca to the wild type of this taxon and apply the name V. labruscana collectively to the confusing series of cultivars and hybrids that have been developed from this species, and which have escaped from cultivation. Missouri plants all belong to this latter group. However, this taxonomic interpretation seems untenable, both because of the heterogeneous origins of the cultivated plants and the fact that they all clearly can be traced back to wild V. labrusca plants, from which they were modified during historical times. The cultivated grapes developed from the wild fox grape include Concord, Catawba, Niagara, Chautauqua, Worden, and many other dark and rosy types.