Britt Slattery, USFWS

Mile-a-minute
Polygonum perfoliatum

Origin: India, Eastern Asia and the islands from Japan to the Philippines

Background
Mile-a-minute, also called Devil's tear-thumb, was experimentally introduced into Portland, Oregon in 1890, and later to Beltsville, Maryland in 1937 but did not become established at either site. An additional unintentional introduction in the 1930s to a nursery site in York County, Pennsylvania was successful and is the likely source of this invasive plant in the mid-Atlantic and northeastern United States. Seeds of the plant may have been spread with rhododendron stock.

Distribution and Ecological Threat
Mile-a-minute weed is found in the northeast from Virginia to New York to Ohio and Oregon. It invades open and disturbed areas, such as fields, forest edges, stream banks, wetlands, roadsides and wetlands. Mile-a-minute grows rapidly, scrambling over existing plants, limiting their photosynthess, which can lead to their death.

Description and Biology

• Plant: an herbaceous, annual, trailing vine in the buckwheat family (Polygonaceae); delicate stems are reddish and armed with downward pointing hooks or barbs; stems are surrounded by distinctive circular, funnel-shaped leafy structures, called ocreae.
• Leaves: light green and shaped like equilateral (equal-sided) triangles with barbs on the undersurface; alternate along the stems.
• Flowers, fruits and seeds: flower buds, and later flowers and fruits, emerge from within the ocreae; flowers are small, white and inconspicuous; fruits are attractive, metallic blue and segmented, each segment containing a single glossy, black or reddish-black seed.
• Spreads: birds are likely the primary long-distance dispersal agents of mile-a-minute weed; transport of seeds short distances by native ant species has been observed; water is also an important mode of dispersal as fruits can remain buoyant for seven to nine days.

Prevention and Control
Manual and chemical methods are effective for controlling mile-a-minute. Seedlings and vines are easy to pull by hand as long as gloves and sturdy clothing are worn. However, pulling vines with mature fruits should be avoided as it may help spread seeds. Contact and systemic herbicides are effective in controlling it. Because the foliage has a waxy covering, the herbicide must be mixed with surfactant to help it adhere to the plant.

Native Alternatives
After eradicating, plant area with native vegetation appropriate to site conditions. Refer to References.

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USDA, NRCS

People use English Ivy (Hedera helix) to cover difficult sites, but it rapidly spreads beyond property boundaries, choking the forest floor and slowly killing trees.

Japanese Honeysuckle (Lonicera japonica) grows vigorously and is known for taking over woodlands Joseph D. RUffner, USDA, NRCS

Britt Slattery, USFWS

Jil Swearingen, NPS

Creeping Euonymus (Euonymus fortunei) invades the woodland floor where it crowds out native plants.

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Publication by USFWS BayScapes Conservation Landscaping Program
http://www.nps.gov/plants/alien/pubs/midatlantic/pope.htm
Last updated: 7 October 2004