North America Native Plant

Puerto Rico Swallow-wort

Botanical name: Cynanchum ephedroides

USDA symbol: CYEP

Life cycle: perennial

Habit: vine

Native status: Native to Puerto Rico  

Synonyms: Metastelma ephedroides (Griseb.) Schltr. (MEEP)  âš˜  Metastelma leptocladon (Decne.) Schltr. (MELE8)   

Puerto Rico Swallow-wort: A Lesser-Known Native Treasure If you’re passionate about native plants and happen to be gardening in Puerto Rico, you might be curious about some of the island’s more obscure botanical treasures. Meet Puerto Rico swallow-wort (Cynanchum ephedroides), a perennial native that’s flying somewhat under the radar in ...

Puerto Rico Swallow-wort: A Lesser-Known Native Treasure

If you’re passionate about native plants and happen to be gardening in Puerto Rico, you might be curious about some of the island’s more obscure botanical treasures. Meet Puerto Rico swallow-wort (Cynanchum ephedroides), a perennial native that’s flying somewhat under the radar in the gardening world.

What Exactly Is Puerto Rico Swallow-wort?

Puerto Rico swallow-wort is a perennial herb that belongs to the milkweed family. As a forb, it’s essentially a non-woody plant that comes back year after year, with its growing points staying close to or below the ground surface. You might also see it listed under its former scientific names, Metastelma ephedroides or Metastelma leptocladon, if you’re digging through older botanical references.

Where Does It Call Home?

This plant is a true Puerto Rican native, found naturally only on the island. As far as we know, its range is limited to Puerto Rico, making it a special part of the island’s unique flora.

Should You Grow Puerto Rico Swallow-wort?

Here’s where things get a bit tricky – and honestly, pretty typical for many lesser-known native species. While Puerto Rico swallow-wort has the botanical credentials of being a true native (which is always a plus!), detailed information about growing it successfully is surprisingly scarce.

The Case for Growing It:

  • It’s a genuine Puerto Rico native, supporting local biodiversity
  • As a perennial, it should provide lasting value in the garden
  • Native plants typically require less water and maintenance once established
  • Supporting rare or lesser-known natives helps preserve genetic diversity

The Challenges:

  • Limited availability in nurseries
  • Scarce information about specific growing requirements
  • Unknown ornamental value or garden performance
  • Propagation methods aren’t well documented

Growing Conditions and Care

Unfortunately, specific growing requirements for Puerto Rico swallow-wort aren’t well documented in horticultural literature. As with many native plants, your best bet would be to mimic its natural habitat conditions as closely as possible.

Since detailed care instructions aren’t readily available, consider these general guidelines for Puerto Rican native plants:

  • Observe where it grows naturally on the island for habitat clues
  • Start with well-draining soil, as many natives prefer this
  • Provide protection from strong winds initially
  • Water regularly until established, then reduce as the plant adapts

The Bigger Picture

Puerto Rico swallow-wort represents something important in the native plant world – it’s one of those forgotten species that deserves more attention. While we may not have all the horticultural details figured out yet, supporting research and cultivation of lesser-known natives like this one helps preserve Puerto Rico’s botanical heritage.

If you’re interested in growing Puerto Rico swallow-wort, consider reaching out to local native plant societies, botanical gardens, or university extension programs. They might have insights about cultivation or even access to seeds or plants. Sometimes the best growing advice comes from fellow gardeners who’ve experimented with unusual natives.

A Plant Worth Knowing

While Puerto Rico swallow-wort might not be the showiest plant in your garden or the easiest to find at your local nursery, it represents the kind of botanical diversity that makes native gardening so fascinating. Every region has these sleeper species – natives that haven’t made it into mainstream horticulture but play important roles in local ecosystems.

Whether you end up growing Puerto Rico swallow-wort or not, knowing about plants like this helps us appreciate the full spectrum of our native flora. And who knows? Maybe you’ll be the gardener who figures out the perfect way to grow this Puerto Rican native and shares that knowledge with the rest of us!

Puerto Rico 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 ephedroides (Griseb.) Alain - Puerto Rico 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