North America Native Plant

Tropical Pondweed

Botanical name: Potamogeton insulanus

USDA symbol: POIN9

Life cycle: perennial

Habit: forb

Native status: Native to Puerto Rico  

Tropical Pondweed: A Hidden Gem for Puerto Rican Water Gardens If you’re looking to create an authentic Puerto Rican water garden, you might want to get acquainted with tropical pondweed (Potamogeton insulanus). This lesser-known native aquatic plant offers a unique opportunity to incorporate truly local flora into your landscape design, ...

Tropical Pondweed: A Hidden Gem for Puerto Rican Water Gardens

If you’re looking to create an authentic Puerto Rican water garden, you might want to get acquainted with tropical pondweed (Potamogeton insulanus). This lesser-known native aquatic plant offers a unique opportunity to incorporate truly local flora into your landscape design, though it comes with some special considerations.

What Makes Tropical Pondweed Special?

Tropical pondweed is a perennial forb that’s completely native to Puerto Rico. Unlike many common garden plants that have been introduced from other regions, this species evolved right here in Puerto Rican waters. As a member of the pondweed family, it’s designed for life in freshwater environments, making it a perfect candidate for ponds, water features, and wetland restoration projects.

Where You’ll Find It Growing Wild

This plant is endemic to Puerto Rico, meaning you won’t find it growing naturally anywhere else in the world. It’s part of the island’s unique aquatic plant heritage, having adapted specifically to local water conditions and climate patterns.

Is Tropical Pondweed Right for Your Garden?

Here’s where things get interesting – and a bit challenging. Tropical pondweed is quite rare in cultivation, which means there’s limited information about exactly how to grow it successfully. However, if you’re passionate about native plant conservation and have experience with aquatic gardening, this could be a rewarding project.

Ideal Garden Settings

Based on what we know about pondweeds in general, tropical pondweed would likely thrive in:

  • Freshwater ponds and water features
  • Wetland restoration projects
  • Native plant conservation gardens
  • Educational or botanical garden displays

Growing Conditions and Care

While specific cultivation requirements for Potamogeton insulanus aren’t well-documented, most pondweeds prefer:

  • Full to partial sun exposure
  • Clean, freshwater environments
  • Stable water temperatures
  • Good water circulation

Since Puerto Rico enjoys a tropical climate year-round, this plant is naturally adapted to warm conditions and wouldn’t be suitable for temperate gardens in other regions.

A Word of Caution: Responsible Sourcing Matters

Because tropical pondweed appears to be quite rare, it’s crucial to source any plants responsibly. Never collect plants from wild populations, as this can harm already vulnerable ecosystems. Instead, look for nurseries that specialize in native Puerto Rican plants or conservation organizations that might have ethically propagated specimens.

Benefits for Local Ecosystems

While we don’t have specific data on tropical pondweed’s wildlife benefits, native aquatic plants typically provide important services like:

  • Oxygen production for aquatic life
  • Habitat for small fish and aquatic invertebrates
  • Water filtration and clarity improvement
  • Erosion control along waterways

The Bottom Line

Tropical pondweed represents a fascinating piece of Puerto Rico’s natural heritage. While it may not be the easiest plant to grow due to its rarity and specific requirements, it offers dedicated native plant enthusiasts a chance to participate in conservation efforts. If you’re considering adding this species to your water garden, approach it as both a gardening adventure and a conservation project.

For most gardeners looking for reliable aquatic plants, you might want to start with other native Puerto Rican water plants that are better established in cultivation. But for those ready to take on a challenge and contribute to preserving local biodiversity, tropical pondweed could be a rewarding addition to the right aquatic setting.

Tropical Pondweed

Classification

Group

Monocot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Liliopsida - Monocotyledons

Subclass

Alismatidae

Order

Najadales

Family

Potamogetonaceae Bercht. & J. Presl - Pondweed family

Genus

Potamogeton L. - pondweed

Species

Potamogeton insulanus Hagstr. - tropical pondweed

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