Caribbean Swallow-wort: A Mysterious Native of Puerto Rico
If you’re a gardener who loves discovering rare and unusual native plants, you might be intrigued by Caribbean swallow-wort (Cynanchum anegadense). This perennial herb is one of those fascinating plants that seems to have flown under the radar of most gardening enthusiasts – and for good reason. Information about this Puerto Rican native is surprisingly scarce, making it something of a botanical mystery.
What is Caribbean Swallow-wort?
Caribbean swallow-wort is a perennial forb native to Puerto Rico. As a member of the milkweed family, it shares characteristics with its more famous relatives, though it lacks the woody tissue that would make it a shrub or tree. Instead, it’s classified as an herbaceous plant – essentially a non-woody perennial that dies back to its roots each year and regrows from underground structures.
You might occasionally see this plant listed under its former scientific name, Metastelma anegadense, though Cynanchum anegadense is the current accepted name in botanical circles.
Where Does It Grow?
This native plant calls Puerto Rico home, and as far as we know, that’s where its natural range begins and ends. For a plant to be so geographically limited suggests it has very specific habitat requirements – though unfortunately, those requirements aren’t well documented in cultivation guides.
The Challenge of Growing Caribbean Swallow-wort
Here’s where things get interesting (and a bit frustrating for eager gardeners): there’s remarkably little information available about successfully growing Caribbean swallow-wort in home gardens. This lack of cultivation data presents both an opportunity and a challenge.
What We Don’t Know
The list of unknowns about this plant is extensive:
- Specific growing conditions and soil preferences
- USDA hardiness zones (though likely limited to tropical zones)
- Mature size and growth rate
- Specific wildlife and pollinator benefits
- Propagation methods
- Landscape design applications
Should You Try Growing It?
The honest answer is: it’s complicated. While Caribbean swallow-wort isn’t listed as invasive or noxious, the extreme lack of cultivation information makes it a risky choice for most gardeners. Without knowing its specific needs, you’d essentially be conducting your own gardening experiment.
If you’re determined to work with native Puerto Rican plants, you might have better success with other well-documented native species that offer similar ecological benefits with proven cultivation methods.
For the Adventurous Gardener
If you’re in Puerto Rico and want to attempt growing this mysterious native, here are some general guidelines based on what we know about related plants:
- As a tropical native, it likely prefers warm, frost-free conditions
- Being in the milkweed family, it may attract butterflies and other pollinators
- Look for it in its natural habitat to observe growing conditions
- Only source from reputable native plant suppliers
The Bigger Picture
Caribbean swallow-wort represents an important reminder that many native plants remain understudied and underutilized in horticulture. While this makes them challenging to grow, it also highlights the need for more research into our native plant heritage.
For most gardeners, especially those outside Puerto Rico, focusing on well-documented native plants in your local area will provide better results and more reliable ecological benefits. But for botanically inclined gardeners in Puerto Rico, Caribbean swallow-wort might represent an interesting challenge – just be prepared for some trial and error along the way.
