Flower:

Branching cluster to 6 inches long of stalked flowers, forming at the tip of this year's side branches of older woody stems. Flowers are about ¼ inch across, have 5 green to whitish petals and 5 green sepals, with male and female flowers on separate plants. Male flowers have 5 stamens with yellow tips.

Female flowers have 5 short, non-functioning stamens surrounding a stout style with a lobed stigma at the top.

Leaves and stems:

Leaves are alternate, 2 to 4 inches long and about half as wide, generally oblong-elliptic or sometimes widest above the middle, finely serrated around the edges, hairless, rounded or slightly tapered at the base, often with a long taper to the sharply pointed tip (acuminate), on a hairless stalk about ¾ inch long. Leaves turn yellow in fall.

New stems are green becoming gray-brown and woody with age, the bark lightly textured with scattered grayish pores (lenticels), and peeling or flaking on older stems. The trunk can grow to 2½ inches in diameter. Stems loosely twine around trees and other structures for support, but as a supporting tree expands the vine does not loosen its grip, which can constrict the expansion of the tree but not usually kill it. In more open areas plants sprawl across the ground and become more shrub-like.

Fruit:

Fruit is round, about ½ inch in diameter, initially green, the outer casing turning orange to red in late summer, splitting open in fall to reveal the 3-sectioned, bright red, berry-like fruit inside. Fruits persist through winter.

Notes:

Similar is Round-leaf Bittersweet (Celastrus orbiculatus), a highly invasive species that is a relative newcomer to Minnesota. It is most easily distinguished while flowering (C. orbiculatus flowers are in the leaf axils) or fruiting (fruits have yellow casings); see the Round-leaf Bittersweet page for more detail and comparative images. Buyer beware: American Bittersweet is available in the nursery trade and some vendors advertise selling it, but it turns out to be Round-leaf Bittersweet instead. This isn't necessarily intentional, but just shows that those selling it can't always tell the difference, either. Know your source!