These vines are not the European wine grape Vitis vinifera, but Vitis labrusca, known as Concord grape or fox grape. While most of the vines in the courtyard are a red variety, there are several vines that bear white grapes. (Some experts contend that the Concord grape may have some small admixture of Vitis vinifera in its genetic makeup. Like those of the European wine grape, the flowers of the Concord grape are hermaphroditic; those of grapes native to North America are not.) The European grapevine is not reliably hardy throughout New York State, and the Concord grape planted here was doubtless chosen for its cold-hardiness and disease-resistance. Advances in viticulture have now made it possible to grow more varieties of Vitis vinifera even in Upstate New York.