Invasive Species of Concern in Maryland

ANNAPOLIS, MD (July 12, 2004) - porcelain berry Porcelainberry (Ampelopsis brevipedunculata) is familiar to almost everyone, even if they can’t name it. Often mistaken for the native grape, Porcelainberry is a deciduous vine of the grape family (Vitaceae). Popular in the horticultural trade for its foliage and colorful berries, it has escaped and become an aggressive invader in our region, especially along streambanks, pond and lake edges, and in open “edge” areas of the urban landscape. The vine climbs by tendrils and can completely cover other, plants. As it climbs, it attacks the shrub, sapling and sub-canopy levels of forest edges. It forms dense green mats as it out-competes our native species for light, water, and nutrients. Summer is high season for Porcelainberry in the Mid-Atlantic states, so the Maryland Invasive Species Council (MISC) has chosen it as July’s “Invader of the Month.”

The leaves of Porcelainberry are bright green, coarsely toothed, and slightly hairy on the underside. They vary from a simple, heart-shaped “grape leaf” form, to a slightly three- to five-lobed shape, to a deeply dissected lobed form. The leaves are arranged alternately on the stem, and often leaves with very different lobe patterns appear on the same stem at the same time. The colorful fruits are a distinguishing characteristic. They are hard, Ľ inch berries, with a porcelain-like sheen, colored green, pale lilac, yellow, white, and blue in the same cluster at the same time.

Porcelainberry is native to eastern Asia, including China, Korea, Japan, and eastern Russia. It was introduced as bedding, shading, and landscape planting material in the 1870s and is still widely used and promoted in some areas. Birds and small mammals spread the seeds, which germinate readily in the soil after natural or human disturbance. Porcelainberry grows well in most soils and once established, is difficult to remove without disturbing the roots of more desirable plants.

Like other aggressive vines, Porcelainberry can cover trees, shutting out light and causing them to weaken and collapse under the weight. Native grape vines are sometimes mistaken for Porcelainberry and cut down. Correct identification is crucial because native grapes produce important wildlife food and cover, and since they evolved with the trees that they use as supports, they do not cause the kind of harm that Porcelainberry does with its immense biomass. Native grapes with their purple-blue, hanging, grape clusters can be easily distinguished from porcelainberry’s multicolored fruits, which are arranged in a flattened, shallow, cluster. In addition, cut stems of Porcelainberry have white centers or “pith”; native grape stems have brown pith.

Some native alternatives to Porcelainberry include virgin’s bower (Clematis virginiana), trumpet creeper (Campsis radicans), and trumpet honeysuckle (Lonicera sempervirens). For more information about porcelainberry and other Invasive Species of Concern, visit www.mdinvasivesp.org or call 410.841.5920.

photos available electronically on request