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Pale Swallow-wort, European Swallow-wort
Family: Asclepiadaceae;
Genus: Cynanchum;
Species: rossicum;
Synonyms:
Vincetoxcum rossicum
Growth Form: Vine
General:
Herbaceous, perennial vine twines 3-6 feet high.
Flowers:
Maroon to pink with 5, pointed, hairless, triangular petals that are twice as long as wide.
Fruits and Seeds:
Milkweed-like, slender and tapered, 1 - 3 inches long turn brown when ripe, wind dispersed; Seed on silky filaments. Reproduction primarily by seed; plants may resprout from buds located on root crown.
Leaves:
Dark green, shiny, opposite, 1 - 4 inches long, toothless, narrowly to broadly oval-shaped with pointed tips.
Stems or Branches:
Single, sometimes branching.
Threatens:
Threatens most upland community types including woodlands, forests, grasslands, and savannas; can persist in sun or shade.
Look-Alikes:
Milk & Honey Vine (Blue Vine), Cynanchum leave (Ampelamus albidum); flowers cream or yellowish white, stems and leaves with a milky sap, base of leaf blades heart-shaped.
Distribution:
Native to the Ukraine region of Eastern Europe. Has been reported in New York,
Massachusetts, Pennsylvania, New Jersey, Indiana, Connecticut, New Hampshire, and
Michigan.
Other Links:
http://www.dnr.state.wi.us/invasives/fact/swallowwort_pale.htm http://www.nps.gov/plants/alien/fact/cyro1.htm
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 PSW open seed pod Larissa L. Smith, Cornell University
 PSW flower Antonio DiTommaso, Cornell University
 PSW vine and seed pods Wisconsin Department of Natural Resources
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