Persicaria perfoliata (L.) H. Gross
Polygonum perfoliatum L.
Ampelygonum perfoliatum (L.) Roberty & Vautier
Asiatic Tearthumb, Devil’s Tail, Mile-a-minute Vine, Mile-a-minute Weed, Mile-a-minute Knotweed
This Asian vine, introduced to North America in the 1930s, is spreading rapidly, and considered a serious invasive threat.
Identification: I first encountered this vine on a rainy afternoon at my sister’s home in Phoenix, MD. It had engulfed nearly everything else, except for tall black walnut trees, in the wooded area behind her yard. It grows up to six inches per day, and is as effective as oriental bittersweet or kudzu at overwhelming and killing native plants. Mile-a-minute vine has leaves that are almost perfect triangles, small curved barbs along its stems, and saucer-shaped leaves (ocreas) at its stem nodes. It develops tightly packed clusters of 10-30 lobed blue fruits, each about ⅛-¼" (3.2-6.3 mm) around.
Persicaria perfoliata on Wikipedia
Persicaria perfoliata on the Plant Conservation Alliance’s Alien Plant Working Group Least Wanted List
Persicaria perfoliata at the United States Department of Agriculture Forest Service (PDF)
Persicaria perfoliata on Wikimedia Commons
Persicaria perfoliata on Forestry Images
Persicaria perfoliata on eFloras
Persicaria perfoliata description by Thomas H. Kent, last updated 12 Oct 2018.