Japanese wisteria (Wisteria floribunda) — identification, habitat & look-alikes

Japanese wisteria is a woody vine native to Japan and grown in U.S. gardens. Its long purple flower clusters hang down in spring and open from the base toward the tip. The raw seeds are poisonous.

Appearance

Growth form: This woody vine can climb 10–25 ft (3–8 m) or more by twining around support.
Leaves: Each leaf is made of many smaller leaflets, usually 15–19.
Flowers: Fragrant purple to pink flowers hang in clusters about 12–18 in (30–46 cm) long. Flowers open from the base of each cluster toward its tip.
Flowering time: In North Carolina, it blooms in spring as the leaves emerge.
Fruit: Flat, fuzzy pods follow the flowers and may remain into winter.

Look-alikes

Chinese wisteriaWisteria sinensis

Japanese wisteria usually has longer hanging flower clusters that open from base to tip. Chinese wisteria (Wisteria sinensis) often has shorter clusters that open nearly together. Viewed from above, their vines twine in opposite directions.

Why they get mixed upBoth are purple-flowered Asian garden vines.

American wisteriaWisteria frutescens

American wisteria (Wisteria frutescens) has flower clusters that are usually no more than 6 in (15 cm) long and open after leaves appear. Its seed pods are smooth, while Japanese wisteria's are fuzzy.

Why they get mixed upBoth have hanging purple flower clusters.

Where it lives

Typical habitats: gardens
natural areas in North Carolina
Range: Native to Japan, it is grown in the United States and has escaped cultivation in North Carolina, where it is considered .
Preferred conditions: In North Carolina it grows best in full sun and can handle a range of soils. It can grow outdoors in 4–9.

Cautions

Cautions: The raw seeds are poisonous.

Name and classification

Varieties and forms: Garden selections include pink-flowered 'Rosea', the especially long-flowered 'Macrobotrys', and the white-flowered form alba.

Conservation

IUCN Red List: NENot EvaluatedNot yet assessed

Culture and stories

Culture and stories: A sturdy arbor and regular pruning are needed to manage its heavy, fast-growing stems.

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