North America Non-native Plant

European Swallow-wort

Botanical name: Cynanchum rossicum

USDA symbol: CYRO8

Life cycle: perennial

Habit: vine

Native status: Non-native, reproduces and persists in the wild in Canada âš˜ Non-native, reproduces and persists in the wild in the lower 48 states  

Synonyms: Cynanchum medium auct. non R. Br. (CYME5)  âš˜  Vincetoxicum medium auct. non (R. Br.) Decne. (VIME4)  âš˜  Vincetoxicum rossicum (Kleopow) Barbarich (VIRO9)   

European Swallow-wort: The Invasive Vine You Should Never Plant If you’ve stumbled across European swallow-wort (Cynanchum rossicum) in your research or spotted it in the wild, here’s the most important thing you need to know: don’t plant it! This perennial vine might look innocent enough with its small white flowers ...

European Swallow-wort: The Invasive Vine You Should Never Plant

If you’ve stumbled across European swallow-wort (Cynanchum rossicum) in your research or spotted it in the wild, here’s the most important thing you need to know: don’t plant it! This perennial vine might look innocent enough with its small white flowers and heart-shaped leaves, but it’s actually a botanical troublemaker that’s causing serious problems across North America.

What is European Swallow-wort?

European swallow-wort is a non-native perennial herb that belongs to the milkweed family. Originally from eastern Europe and western Asia, this climbing vine has made itself far too comfortable in North American landscapes. Unlike our beneficial native plants, this species reproduces aggressively in the wild and tends to persist without any human help – and that’s exactly the problem.

You might also see this plant referred to by its scientific synonyms, including Vincetoxicum rossicum, but whatever you call it, the message remains the same: it’s trouble.

Where You’ll Find This Invasive Species

European swallow-wort has spread throughout much of eastern North America, establishing populations in British Columbia, Ontario, Quebec, Connecticut, Indiana, Massachusetts, Michigan, Missouri, New Hampshire, New Jersey, New York, and Pennsylvania. If you live in any of these areas, you’ve probably encountered this vine without even realizing it.

Why European Swallow-wort is Bad News

This isn’t just another weedy plant – European swallow-wort has earned serious invasive status across multiple states:

  • Connecticut lists it as Invasive, Prohibited
  • Michigan classifies it as Invasive
  • New York has it listed as Prohibited
  • Wisconsin also lists it as Prohibited

These classifications exist for good reason. European swallow-wort is incredibly aggressive, forming dense colonies that crowd out native plants. It climbs over and smothers other vegetation, fundamentally altering the ecosystems where it establishes. Unlike native plants that support local wildlife, this invasive species offers little to no benefit to native birds, insects, or other wildlife.

How to Identify European Swallow-wort

Knowing how to spot this invasive vine is crucial for protecting your local ecosystem. Here’s what to look for:

  • Heart-shaped leaves arranged in opposite pairs along the stem
  • Small white flowers clustered together (blooming from June to September)
  • Twining, climbing growth habit that can reach several feet in height
  • Seed pods that split open to release seeds with silky white hairs (similar to milkweed)
  • Perennial growth from underground rhizomes

What to Do If You Find It

If you discover European swallow-wort on your property, don’t panic – but do take action. Small populations can be hand-pulled, preferably before the plants set seed. For larger infestations, you may need to contact local extension services or invasive species management programs for guidance on effective removal strategies.

Remember: never compost this plant or move it to another location. The seeds can remain viable and spread the problem further.

Better Alternatives for Your Garden

Instead of risking the ecological damage that comes with European swallow-wort, consider these native climbing alternatives:

  • Wild ginger (Asarum canadense) for ground cover
  • Native honeysuckles like coral honeysuckle (Lonicera sempervirens)
  • American groundnut (Apios americana)
  • Native milkweeds like common milkweed (Asclepias speciosa) for similar flowers

These native options will provide the aesthetic appeal you’re looking for while supporting local wildlife and maintaining healthy ecosystems.

The Bottom Line

European swallow-wort might seem like an easy-care perennial vine, but its invasive nature makes it completely unsuitable for responsible gardening. The short-term appeal of its white flowers and climbing habit isn’t worth the long-term ecological damage it causes. Instead, choose native alternatives that will give you beautiful results while supporting the local environment.

Remember: the best gardeners are stewards of their local ecosystems. By saying no to invasive species like European swallow-wort, you’re helping protect the native plants and wildlife that make your region unique.

European Swallow-wort

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Gentianales

Family

Asclepiadaceae Borkh. - Milkweed family

Genus

Cynanchum L. - swallow-wort

Species

Cynanchum rossicum (Kleopow) Borhidi - European swallow-wort

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA