Round leaf (Oriental) bittersweet (Celastrus orbiculatus) is a perennial deciduous, climbing, woody vine that can grow to lengths of 60 feet and up to 4 inches in diameter. The striated bark is brown to dark brown. The smooth twigs can range from light gray to dark brown. The alternate, elliptical to rounded leaves are light green and 2-5 inches long. Small, inconspicuous, axillary, greenish white flowers bloom from May to early June. Small, round fruits are green when young; ripen to yellow; then split to reveal showy, scarlet berries that persist into winter. Celastrus orbiculatus is often found in old home sites, fields, and road edges. The fast-growing vines can cover, shade, and outcompete other vegetation, and even girdle and kill large trees.