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Invasive Species Sheet - Mile-a-Minute

Invasive Species Identification Sheet

Mile-a-Minute (Polygonum perfoliatum L)

Alternate Common Names: Mile-a-minute Weed; Mile-a-minute; Devil’s or Asiatic Tearthumb

  • annual vine; branched, weak stems climb/sprawl densely over other plants
  • backward-hooked prickles on vine, flower stalks, leaf stalks and veins on back of leaf
  • below each leaf, the angular vine stem is surrounded by a green, saucer-shaped sheath
  • leaves alternate; triangular; about 1"-3" long and as wide or wider than long
  • leaf stalk attached to the back of the leaf near its base (peltate)
  • inconspicuous flowers clustered on short stem growing from the saucer-shaped sheaths
  • fruit fleshy, berry-like; about 1/4" across; shiny, metallic blue when ripe

Mile-a-minute Vine seeds sprout in Spring and the vine grows rapidly to 20' or 25'. It continues to produce flowers and fruits until killed by frost. The leaves are frequently a perfect triangle, sometimes with slightly eared or heart-shaped bases. The green, leaf-like, saucer-shaped ocreae and the fleshy fruits distinguish Mile-a-minute Vine from native Tearthumb species (which also have backward-hooking prickles). The leaves and ocreae (saucer-shaped sheaths surrounding the stem) are light green or light bluish-green. The vine stems, often reddish, are noticeable after the plant is frost killed. Fruits are light green or purple before ripening to shiny, metallic blue;
and may be found on dead vines.

Mile-a-minute Vine seeds sprout best on sites covered by decayed leaf mulch. For vigorous growth, the seedlings need full sun. The vine smothers herbaceous plants, shrubs, and young trees in open areas such as meadows, forest edges, logged forests, streambanks, and utility rights-of-way. The fruits float and are eaten by birds, small mammals, and deer.