Wisteria sinensis (Sims) DC.
CC = *
CW = 5
MOC = 4
Family - Fabaceae/Faboideae
Habit - Liana, or shrublike in the absence of support.
Leaves - Alternate, odd-pinnately compound, petiolate, stipulate. Petioles 3-7 cm long, the rachis 15-25 cm long. Leaflets 5-8 cm long, 2.0-4.0 cm wide, emerging at time of flowering, bronze colored when young, the surfaces moderately to densely appressed-hairy when young, becoming glabrous or nearly so at maturity. Stipules 1-3 mm long, hairlike, early deciduous.
Inflorescences - Showy terminal racemes 10-20 cm long, pendent, bracteate, with numerous flowers maturing more or less at the same time, the flower stalks 8-20 mm long, densely pubescent with short, fine, curved to spreading hairs, lacking club-shaped glands.
Flowers - Calyces 4.0-7.5 mm long, light green, but often strongly purplish-tinged, moderately to densely pubescent with short, fine, curved to spreading hairs, lacking club-shaped, stalked glands. Corollas papilionaceous, 15-22 mm long, bluish purple to lilac, or rarely pink, the banner with the expanded portion bent backward near the base, often with a white and/or light yellow to light green region toward the base, the wings and keel sometimes darker at their tips.
Fruits - Legumes 10-18 cm long, narrowly oblong, densely velvety-hairy, with 2-12 seeds. Seeds 11-14 mm long, 10-14 mm wide, more or less circular in outline, strongly flattened.
Flowering - April - May.
Habitat - Upland forests, fencerows, roadsides, old homesites, usually persisting from former cultivation.
Origin - Native to China.
Lookalikes - W. frutescens.
Other info. - This strikingly showy species is often cultivated but rarely escapes in Missouri. In the U.S. it is found mainly in the southeast. The plant can grow as a sturdy liana on other vegetation, or as a more or less freestanding shrub. It is easily recognized by its large, showy inflorescences of bean-pattern flowers. It differs from the native wisteria (W. frutescens) in having flowers with the banner petal reflexed from the base, and which have no club-shaped glands on their stalks.
Photographs taken in Sullivan, Franklin County, MO, 4-21-2020, and at Millstream Gardens Conservation Area, Madison County, MO, 4-28-2020 (SRTurner).