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Cynanchum laeve is a vining perennial herb native to eastern and central U.S. states and Ontario. Common names include sand vine, honeyvine, honeyvine milkweed, bluevine milkweed, climbing milkweed, and smooth swallow-wort.[2] It is considered a noxious weed in many US states.The root system of C. laeve can cause it to be very difficult to eradicate, especially in agricultural fields.[3] It is also a food plant for caterpillars of monarch butterflies[4] and larvae of the milkweed tussock moth.[5]C. laeve is a noxious weed[citation needed] that can cause eye irritation if touched and can stop your heart if consumed.[6] This can be especially problematic in livestock.[7]

Cynanchum laeve
Cynanchum laeve NRCS-1.jpg
Scientific classification
C. laeve
Binomial name
Cynanchum laeve

Ampelamus albidus
Ampelamus laevis
Gonolobus laevis

Cynanchum laeve'[1]



Cynanchum laeve was originally described in 1803 as Gonolobus laevis Michx. Mixed elements on the type sheet that was published has lead to confusion around the correct nomenclature.[8] Currently under the International Plant Names Index it is listed as Cynanchum laeve Pers.[9] Synonymous plant names include Ampelamus albidus (Nutt.) Britton, Ampelamus laevis (Michx.) Krings, and Gonolobus laevis Michx.[10] Cynanchum laeve is in the Apocynaceae, or milkweed family. Cynanchum, or swallow-wort genus, and the laeve, which is a specific epithet meaning smooth .[10]


Like bindweed and some other members of the Convolvulaceae, Cynanchum laeve is a twining vine with heart-shaped leaves commonly found in roadsides, fence rows, fields, and disturbed areas. However, C. laeve is easily recognized as a member of the Apocynaceae by its opposite leaves,[11] milky sap and distinctive flowers and follicles ("milkweed pods"). The seeds are wind dispersed and can travel long distances. Each plant can produce up to 50 pods. The root system is fleshy and brittle with a large taproot with other lateral roots, these roots can grow up to 6 feet deep. Developing stems are a light pink that excrete a milky sap when the stem is broken.[3] Flowers have 5 white petals that are vase shaped. These flowers are found in clusters along shorter stalks on the plant.[3] C. laeve flowers between June and September.[3]

Distribution and HabitatEdit

Cynanchum laeve can be found in the eastern and central United States including Ontario in Canada.[12] C. laeve can be found in wetland areas in the arid West, Atlantic and Gulf Coastal Plain, Eastern mountain and Piedmont, the Great Plains, Midwest, and the North Central and North Eastern United States.[10][13][14] The habitat for C. laeve is typically disturbed habitats such as: thickets, low moist fields, riverbanks, fence rows, and cultivated fields.[3]

Conservation StatusEdit

In Pennsylvania, Cynanchum laeve is listed as endangered.[10]C. laeve is considered a noxious weed in several states, and can be very difficult to eradicate from fields because of its deep, extensive root system. These root systems have a habit to climb up other plants, this causes problems during crop harvesting season.[3]

Moth UseEdit

Cynanchum laeve is a food plant for the caterpillars of monarch butterflies.[4][15] Larvae of Euchaetes egle, the milkweed tussock moth, both in the Eastern and Western United States use C. laeve.The larvae of these moths feed off of Cynanchum laeve and other plants when developing.[5]


Cynanchum laeve is considered a noxious weed.[citation needed] C. laeve is not an edible plant. If you come into contact with it, the sap can cause eye irritation damaging the mucus membrane and the eye. If C. laeve is consumed it can stop your heart.[6] The cardenolides in C. laeve is a large problem in livestock such as cattle, sheep, and goats. The hay fed to livestock can contain C. laeve which is a problem. It is recommended by the US Fish and Wildlife Service to take precautionary steps. These steps include not grazing hungry animals in pastures containing C. laeve, to eradicate it from driveways and trails, and to closely observe livestock that have just been introduced to areas containing C. laeve.[7]


  1. ^ 1913 illustration from Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner's Sons, New York. Vol. 3: 36
  2. ^ "Cynanchum laeve (Michx.) Pers. — The Plant List". Retrieved 2018-11-28.
  3. ^ a b c d e f "Ohio Weedguide". Retrieved 2018-11-28.
  4. ^ a b Kansas Native Plants: Butterfly Gardening
  5. ^ a b "CAS - Catawba Authentication Service". Retrieved 2018-11-14.
  6. ^ a b "Common Non-Edible Plants - Eat The Weeds and other things, too". Eat The Weeds and other things, too. Retrieved 2018-11-28.
  7. ^ a b Delserone, Leslie M. (2014-07-03). "The Xerces Society for Invertebrate Conservation (". Journal of Agricultural & Food Information. 15 (3): 153–158. doi:10.1080/10496505.2014.924378. ISSN 1049-6505.
  9. ^ IPNI Plant Name Details. Retrieved 2018-11-28.
  10. ^ a b c d "Plants Profile for Cynanchum laeve (honeyvine)". Retrieved 2018-11-28.
  11. ^ "Cynanchum laeve page". Retrieved 2018-11-28.
  12. ^ "US Southeast flora atlas". Retrieved 2018-11-28.
  13. ^ "Maryland Biodiversity Project - Honey Vine (Cynanchum laeve)". Retrieved 2018-11-28.
  14. ^ "Cynanchum laeve - Species Details". Atlas of Florida Plants. Retrieved 2018-11-28.
  15. ^, Jim Lovett -. "Monarch Watch : Milkweed : Photo Guide : Cynanchum laeve (Sand Vine [Blue Vine] Milkweed)". Retrieved 2018-11-28.