Black Swallowwort
Cynanchum louiseae (formerly Cynanchum nigrum) |
Other common names:
Black Dog Strangling Vine, Dog Strangling Vine

Other scientific names:
Cynanchum nigrum, Asclepias nigra, Vincetoxicum nigrum

Family:
Dogbane Family (Apocynaceae), (Milkweed Family (Asclepiadaceae))

Group:
Swallowworts

Distinctive features:
Opposite leaves on a vine, milkweed-like seed pods and seeds.

Similar species:
Pale Swallowwort (Cynanchum rossicum) - very similar.
White Swallowwort (Cynanchum vincetoxicum) - very similar, has white flowers.

Flowers:
Summer; Green/Brown; 5 parts (petals); 5-petals, dark purple/dark brown, petals fuzzy, 1/4" wide, late spring & summer.

Leaves:
Opposite/Whorled, Entire; Opposite pairs, sometimes in a whorl, egg-shaped.

Height:
Vine, 2-6 feet long.

Stem:
Vine.

Fruit/Seeds:
In a pod closely resembling those of milkweed. but smaller.

Habitat:
Fields and Open Areas; Open areas, forest edges.

Books:
Newcomb's Wildflower Guide: 326
Peterson's Field Guide to Wildflowers: 390
ROM Field Guide to Wildflowers of Ontario: 139

Native/Non-native:
Non-native

Status:
Common.

Notes:
This is a highly invasive alien plant, that will aggressively take over an area once it gets a chance. Pull it up before it gets a foothold.

Origin and Meaning of Names:
Scientific Name: nigrum: black

Photographs:
5 photographs available, of which 3 are featured on this page. SCROLL DOWN FOR PHOTOGRAPHS.

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