Difference Between American & Chinese Wisteria

Size and Form

• American wisteria grows slightly larger on average than Chinese wisteria does, according to the Missouri Botanical Garden. The American vine achieves lengths of 30 feet, while Chinese wisteria grows to 25 feet. The two vines also differ in the direction they twine around a structure. American wisteria grows clockwise on a structure, while Chinese wisteria grows in a counterclockwise manner.

Flowers

• The flowers of the American wisteria grow on 6-inch long hanging clusters known as racemes. The racemes of the Chinese wisteria reach lengths of 12 inches. American wisteria flowers are shades of lilac-purple, while the blooms on the Chinese wisteria are a violet-blue tint. Both vines produce their flowers just as the leaves emerge, but while this occurs on American wisteria in April and May, it occurs on Chinese wisteria during May and June.

Foliage

• Compound leaves are a feature of the wisteria vines, but the number of leaflets on the American and Chinese wisterias differs. American wisteria has between nine and 15 leaflets, each shaped like a small lance and growing on the central axis of each leaf. Chinese wisteria has fewer leaflets, with as few as seven but no more than 13 on each leaf. Both vines have dark green foliage.

More Differences

• American wisteria is somewhat more tolerant of warmer climates, growing into U.S. Department of Agriculture plant hardiness zone 9, while Chinese wisteria grows only into zone 8. Chinese wisteria becomes more massive than American wisteria, requiring a sturdy, strong structure on which to grow. Chinese wisteria is more invasive than American wisteria is, escaping cultivation and establishing itself in the wild.