Ontario Wildflowers website

Pale Swallowwort
Cynanchum rossicum

Other common names: Dog Strangling Vine, European Swallowwort, Russian Swallowwort

Other scientific names: Cynanchum medium, Vincetoxicum medium, Vincetoxicum rossicum

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

Group: Swallowworts

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

Similar species:
  •   Black Swallowwort (Cynanchum louiseae)

  •   White Swallowwort (Cynanchum vincetoxicum)


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

Leaves: 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.

Native/Non-native: Non-native

Status: Common.

Notes: Swallowworts are highly invasive alien plants, that will aggressively take over an area once they get a chance. Pull them up before they get a foothold.

See Also:
  •   Swallow-wort: Monarch Menace, from The Monday Garden, by Sue Sweeney


Photographs: 68 photographs available, of which 13 are featured on this page. SCROLL DOWN FOR PHOTOGRAPHS.

Range Map is at the bottom of the page

Pale Swallowwort (Cynanchum rossicum)

This is a dangerously invasive plant. It grows fast, spreads rapidly, and climbs all over other vegetation, overcoming it.

Pale Swallowwort (Cynanchum rossicum)

This plant is a vine, and it climbs by twisting around other plants, including itself.

Pale Swallowwort (Cynanchum rossicum)

The purple/brown flowers. Five petals, only about 1/4" across.

Pale Swallowwort (Cynanchum rossicum)

Pale Swallowwort (Cynanchum rossicum)

Pale Swallowwort (Cynanchum rossicum)

Pale Swallowwort (Cynanchum rossicum)

Pale Swallowwort (Cynanchum rossicum)

The shiny egg-shaped leaves and seed pods forming.

Pale Swallowwort (Cynanchum rossicum)

Leaves, in pairs along the stem.

Pale Swallowwort (Cynanchum rossicum)

Seed pods opening up to disperse the seeds, which are attached to fluffy parasols which allow them to be carried great distances.

Pale Swallowwort (Cynanchum rossicum)

Pale Swallowwort (Cynanchum rossicum)

Pale Swallowwort (Cynanchum rossicum)

Colony of Pale Swallowwort in the winter.


Range map for Pale Swallowwort (Cynanchum rossicum)

PLEASE NOTE: A coloured Province or State means this species occurs somewhere in that Province/State.
The entire Province/State is coloured, regardless of where in that Province/State it occurs.

(Range map provided courtesy of the USDA website and is displayed here in accordance with their Policies)