Black dog-strangling vine, black swallowwort: Cynanchum louiseae (Gentianales: Asclepiadaceae)

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Black dog-strangling vine, black swallowwort	USDA PLANTS Symbol: CYLO11 USDA ARS GRIN: 405616 ITIS: 506929 NAPIS: PAMAEBD
Cynanchum louiseae Kartesz & Gandhi
Taxonomic Rank: Magnoliopsida: Gentianales: Asclepiadaceae
Synonym(s): Louis' swallow-wort
Black swallowwort is an herbaceous, twinning, perennial vine. Leaves are opposite, dark green, oval, shiny, entire, 3-4 in. (7.6-10.2 cm) long and 2-3 in. (5.1-7.6 cm) wide. Flowering occurs in June to July, when dark purple, 5-petaled, star-shaped flowers appear in clusters. Flowers are approximately 0.25 in. (0.6 cm) across and covered with white hairs. Fruit are pods, similar to milkweed pods, which are slender, 2-3 in. (5.1-7.6 cm) long and split to reveal small seeds with tufts of white hair. The hair allows the seeds to be readily dispersed. Plants have rhizomes that sprout new plants. Black swallowwort invades upland areas with a wide range of light and moisture conditions. Black swallowwort is native to Europe and escaped from a botanical garden in Massachusetts.

Identification, Biology, Control and Management Resources

Plant Invaders of Mid-Atlantic Natural Areas - National Park Service and U.S. Fish and Wildlife Service
Weeds Gone Wild: Alien Plant Invaders of Natural Areas - Plant Conservation Alliance
Weed of the Week - USDA Forest Service
Element Stewardship Abstract - The Nature Conservancy
Invasive Plant Atlas of New England - University of Connecticut
Biological Control of Invasive Plants in the Eastern United States - USDA Forest Service

Distribution Map

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Developed by The University of Georgia - Center for Invasive Species and Ecosystem Health.
Last updated on Thursday, February 14, 2013 at 02:47 PM