Britt Slattery, USFWS
Origin: India, Eastern Asia and the islands from
Japan to the Philippines
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
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.
After eradicating, plant area with native vegetation
appropriate to site conditions. Refer to
[ Home ] [ Contents ]