This introduced woody vine branches occasionally and can reach 50' in length. Boston Ivy can easily climb tree bark, wooden fences, concrete masonry, and brick or stone walls. In the absence of such supportive surfaces, it sprawls across the ground. The lower stems of mature vines are brown and woody; they can span several inches across and form small brown rootlets that can cling to various surfaces. The upper stems are hairless and vary in color from green to bright orange-red; they produce branched tendrils that have suckers at their tips. These suckers are shaped like small disks and can cling to various surfaces as well. Immature plants that are beginning to develop have trifoliate leaves. However, mature plants produce simple alternate leaves along their stems. The mature leaves span up to 6" long and across (excluding the petioles). They are cordate-oval, palmately lobed (usually with 3 lobes), and crenate or slightly undulate along the margins. Their upper surface is medium to dark green, hairless, and rather shiny. Young leaves of mature plants are similar, except they are yellowish green and coarsely dentate along the margins. The petioles of these leaves are long and slender; they are usually light green, but may become bright orange-red during the fall. Occasionally, cymes of flowers are produced from the axils of the leaves. Each cyme can span up to 4" across and long. Each yellowish green flower is about ¼" across, consisting of 5 green petals, 5 stamens with yellow anthers, and a central pistil. The sepals are absent or insignificant. The blooming period occurs during the summer and lasts about 2-3 weeks. The flowers are usually well-hidden in the foliage. Each fertilized flower can produce a juicy berry about 1/3" long that contains 1-3 seeds. The berries are dark blue with a whitish bloom and globoid in shape; their stalks are yellowish green, brownish green, or dull orange-red. The root system consists of a stout woody taproot.