Polygonum perfoliatum electricity allergy


Polygonum perfoliatum is a rapidly growing herbaceous annual vine. Its stems can grow up to 7 m (23 ft.) in length and as much as 15 cm (6 in.) per day. Its dense foliage can quickly cover surrounding vegetation. A characteristic cup-shaped ocrea (or bract) surrounds the stem at the base of the petiole; those of the upper leaves are conspicuously expanded. Stems, petioles and veins on the underside of the foliage are armed with curved, retrorse barbs. The petioles are long and perfoliate. The thin, jointed, highly branched stems are green to reddish-green in color. The alternate leaves are pale green, thin and glabrous. They are 2-8 cm (0.75-3.0 in.) wide and deltoid in shape, being as long as they are wide (this leaf shape gives it one of its common names, devil’s tail). The flowers are borne on racemes 1-2 cm (0.4-0.8 in.) in length that emerge from the ocrea. These inconspicuous white flowers measure 3-5 mm (0.12-0.2 in.), bear three stigmas and often remain closed. Green, berry-like fruits, 5 mm (0.2 in.) in diameter, are produced in June and become a pale, metallic blue color as they ripen. Each fruit contains a shiny, black or reddish-black, nearly round achene 2 mm (0.08 in.) in diameter. Polygonum perfoliatum produces fruit continuously until the first frost, when the plant begins to die back. Dead plants in winter are reddish-brown to tan in color, often forming brittle mats. Page References Fernald 588, Gleason & Cronquist 138, Holmgren 123. See reference section below for full citations.

Polygonum arifolium L. (halberdleaf tearthub) Picture of P. arifolium, Polygonum sagittatum L. (arrowleaf tearthumb) Picture of P. sagittatum, Polygonum scandens var. cristatum (Engelm. & Gray) Gleason (false buckwheat) Picture of P. scandens, Calystegia sepium (L.) R. Br. (wild morning glory) Picture of C. sepium. Other species not listed in table: Polygonum cilinode Michx. (fringed black bindweed) Picture of P. cilinode, Polygonum convolvulus L. (black bindweed) Picture of P. convolvulus

Polygonum perfoliatum is native to east Asia. It has invaded British Columbia, Canada, and was introduced to Oregon with ship ballast in 1890. Polygonum perfoliatum has also been found in Pennsylvania, Ohio, Virginia, West Virginia, Delaware, Washington D.C., Maryland, New Jersey, New York and Mississippi. In New England it was recently found in Connecticut (2000) and Rhode Island (2001).

In 1946, Polygonum perfoliatum was discovered in Pennsylvania in a shipment of rhododendrons, and has since spread to nearby states. It was found in Connecticut in 2000, and although its means of introduction is unclear, it apparently had been extant for a few years before it was reported. Within a year it was reported from Rhode Island, where it was found growing in a rhododendron/azalea nursery.

Abandoned Field, Early Successional Forest, Edge, Pasture, Railroad Right-of-Way, Roadside, Utility Right-of-Way, Vacant Lot, Wet Meadow, Yard or Garden. Currently known from a small number of sites in Connecticut and Rhode Island, Polygonum perfoliatum is usually found in open disturbed areas and abandoned agricultural fields. In Fairfield County, Connecticut it is growing in a planted butterfly garden while in Washington County, Rhode Island it is in a nursery. Interestingly, at the Connecticut site it is spreading into the adjacent early successional forest and has been observed climbing the trunks of trees up to 4 m (13 ft.) high. In other states it has been described along roadsides, stream edges and wet meadows.

Polygonum perfoliatum has the potential to overgrow and outcompete native vegetation. Trees and other plants could suffer mechanical damage due to the weight of this vine. The fact that it is being transported around in nursery stock is also a problem, because it may be planted inadvertently with other plants.