Ampelopsis is a genus of climbing woody vines and shrubs in the grape family, Vitaceae. The genus was established by André Michaux in 1803 and is currently accepted by Plants of the World Online as containing 16 species, with regional floras such as Gleason & Cronquist citing closer to twenty when older circumscriptions are included. Most members produce small greenish flowers in cymose clusters opposite the leaves and bear berries containing two to four seeds; the calyx is shallowly saucer-shaped and the leaves are often deeply lobed or compound, with tendrils — also opposite the leaves — that help the vines clamber over surrounding vegetation.
Common names for the genus include peppervine and porcelainberry, the latter referencing the strikingly colored, mottled blue-purple berries of the most familiar ornamental species. Members are temperate to subtropical in habit and disjunctly distributed across eastern Asia and eastern North America, reaching south into Mexico; the genus is well represented in the mountains of China and in the deciduous forests of the south-eastern United States. Many species were widely planted in the 19th and 20th centuries as fast-growing ornamental climbers for arbors and fences, valued for vigorous growth, attractive fruit, and tolerance of difficult conditions.
The same traits that make Ampelopsis vines effective garden subjects have made at least one species, A. glandulosa (often grown under the older name A. brevipedunculata), a serious invasive weed in the eastern United States, where it climbs over and shades out smaller trees and shrubs and is widely dispersed by birds. Other notable members include A. cordata, native to riparian forests of the central and southern United States; A. japonica, a deciduous climber from East Asia; and the former A. arborea of the south-eastern United States, which modern molecular treatments place in the segregate genus Nekemias. The genus name comes from Ancient Greek ἅμπελος (ampelos), meaning "vine."
Etymology
The genus name Ampelopsis derives from Ancient Greek ἅμπελος (ampelos), meaning "vine," a reference to the close family relationship with true grapes (Vitis) and the climbing, tendril-bearing growth habit shared across the Vitaceae.
Distribution
Ampelopsis has a classic disjunct Asian–American distribution. Native species occur across temperate and subtropical Asia from Turkey, the Caucasus, and Central Asia eastward through China, Korea, Japan, and the Philippines, and through eastern and central North America south into Mexico and Central America. Several species have been widely introduced beyond their native range as ornamentals; POWO records naturalised populations of the genus in much of the north-eastern United States (Connecticut, Maryland, Massachusetts, Michigan, New Hampshire, New Jersey, Pennsylvania, Rhode Island, Vermont, Wisconsin, plus DC), in Great Britain and Ukraine. In Switzerland the genus is represented only by the introduced A. glandulosa, treated as a neophyte by Info Flora.
Taxonomy
Ampelopsis was described by André Michaux in 1803 in Flora Boreali-Americana (1: 159) and is universally placed in the grape family, Vitaceae, within the order Vitales. Plants of the World Online currently accepts 16 species; older floristic treatments such as Gleason & Cronquist (1991) cite about 20, and the GBIF backbone tracks 52 descendant taxa once subspecies, varieties, and synonyms are included. Recognised generic synonyms include Ituterion Raf. (1838) and Vitaeda Börner (1912). Recent molecular work has redrawn the limits of the genus: the south-eastern North American "pepper vine," long treated as A. arborea, is now placed in the segregate genus Nekemias as Nekemias arborea.
Ecology
Ampelopsis vines are characteristic plants of forest edges, riparian corridors, and disturbed mid-successional habitats, where their tendrils let them clamber over shrubs and into the canopy of small trees. The fleshy, bird-dispersed berries are an important dispersal mechanism — and a major reason A. glandulosa spreads so aggressively beyond plantings in eastern North America. Several species act as larval host plants for Lepidoptera, including the leaf-mining moth Bucculatrix quinquenotella and the hawkmoth Sphecodina abbottii.
Cultivation
Most cultivated Ampelopsis are vigorous deciduous climbers used to cover arbors, fences, and walls. PFAF records A. brevipedunculata (porcelainberry) as a fast climber reaching about 20 m and hardy in USDA zones 5–8; A. arborea (pepper vine) as a 10 m climber for zones 6–9; A. humulifolia as a smaller 6 m climber hardy down to zone 4; and A. japonica as a 10 m climber for zones 6–9. The fruits of most species are not worth eating — A. arborea's flesh is thin and described as poor-tasting, and porcelainberry fruits are bland and slimy — so cultivation is essentially ornamental, prized for the colourful blue-purple "porcelain" berries of A. glandulosa and the deeply cut foliage of A. aconitifolia and A. humulifolia. Gardeners in temperate North America should consider invasive risk before planting A. glandulosa, which is increasingly restricted by state laws.
Conservation
The conservation story for Ampelopsis is dominated by the inverse of conservation concern: A. glandulosa (porcelain berry, Amur peppervine) — introduced to the United States in the 1870s as an ornamental — is now an aggressive invader across the eastern US from Wisconsin and Iowa east to the Atlantic coast and from New Hampshire south to Georgia. It climbs over and shades out shrubs and younger trees, smothers larger plants, and is dispersed efficiently by birds, allowing it to colonise roadsides, fields, and floodplains. Delaware banned its sale as of 1 July 2022, and other states have added it to invasive watch lists or noxious-weed regulations. Outside North America the same species is treated as a neophyte in Switzerland and is recorded as introduced in Great Britain and Ukraine.
Cultural uses
Despite belonging to the grape family, Ampelopsis species have only minor culinary use; PFAF rates all four species it covers at no more than 2/5 for edibility, and porcelainberry fruits are described as bland and slimy. Several species figure in traditional East Asian medicine: A. glandulosa is used in traditional Chinese medicine for blood clots, boils, and bruises, and a flavonoid extracted from Ampelopsis — dihydromyricetin (ampelopsin) — is sold today as a dietary supplement and the active ingredient in various herbal tonics.
