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DescriptionThis is a woody vine up to 15' long that branches sparingly. Its stems twine about adjacent vegetation or objects for support, otherwise it tends to form a tangled mound of leafy stems that resembles a bush. At the base of each vine, the outer bark of the narrow trunk is shredded into gray strips, revealing an inner bark that is reddish brown. Young first-year stems are light green to pale reddish green, glabrous, and terete. With age, these stems can become yellowish tan, brown, or orange-red and they may become longitudinally grooved. Along these stems, pairs of opposite leaves occur at intervals. For non-terminal leaves without flowers, individual leaf blades are up to 4' long and 3' across; they are oval, ovate, or obovate in shape and smooth along their margins. The bases of these leaf blades are either narrowly perfoliate, sessile, or they have short petioles. The upper surface of non-terminal leaf blades is yellowish green to medium green and glabrous, while the lower surface is usually whitened and either short-pubescent or glabrous (usually the latter). The upper 1-2 pairs of opposite leaves have similar characteristics to the non-terminal leaves, except they are strongly perfoliate and become conspicuously glaucous during and after the blooming period. The upper surface of the terminal leaf blades is whitish green to whitish gray-blue. For the uppermost pair of leaves, their joined leaf blades may be almost as wide as they are long. About 2-5 sessile whorls of flowers develop along a short flowering stalk from the uppermost pair of leaves. Sometimes secondary whorls of flowers develop from short axillary stalks from the pair of leaves immediately below the uppermost pair. Individual flowers are about 1' long, consisting of a 2-lipped corolla that is pale yellow to orange-yellow and a short tubular calyx. The upper lip of the corolla consists of 4 short upright lobes, while the lower lip of the corolla consists of a single recurved lobe. The base of the corolla is slightly swollen on one side. Exerted from the throat of each corolla, there are 5 stamens and a single style with a knobby stigma. The filaments of the stamens are nearly hairless, except for some sparse hairs below. The blooming period occurs from late spring to early summer and lasts about 2-3 weeks. Depending on the orientation of the vine, some flowers may dangle from their stalks upside down. The flowers are often fragrant. They are replaced by berries that become about 6-7 mm. long at maturity. At this time, they are orange-red to red, globoid-ovoid in shape, and juicy. Each berry contains a few small seeds about 3 mm. long. In the climate of Illinois, the leaves of this vine are deciduous.