North America Native Plant

Potamogeton ×subdentatus

Botanical name: Potamogeton ×subdentatus

USDA symbol: POSU11

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Potamogeton ×subdentatus: A Specialized Native Aquatic Plant for Water Gardens If you’ve ever wondered about creating a truly authentic native water feature, you might want to get acquainted with Potamogeton ×subdentatus. This lesser-known native perennial represents one of nature’s more specialized offerings – an aquatic plant that thrives completely underwater ...

Potamogeton ×subdentatus: A Specialized Native Aquatic Plant for Water Gardens

If you’ve ever wondered about creating a truly authentic native water feature, you might want to get acquainted with Potamogeton ×subdentatus. This lesser-known native perennial represents one of nature’s more specialized offerings – an aquatic plant that thrives completely underwater and plays an important ecological role in freshwater environments.

What Exactly Is Potamogeton ×subdentatus?

Potamogeton ×subdentatus is a native perennial forb that belongs to the pondweed family. Unlike your typical garden perennials, this plant is what botanists call an obligate wetland species – meaning it almost always occurs in wetlands and requires permanent water to survive. It’s a vascular plant without woody tissue, spending its entire life cycle either submersed in water or floating just below the surface.

Where Does It Naturally Grow?

This native species has a somewhat scattered distribution across the United States, naturally occurring in Alabama, Florida, and New York. Its presence in both southeastern and northeastern regions suggests it can adapt to different climate conditions, though it’s always tied to aquatic environments in both regions.

Should You Consider Growing It?

Potamogeton ×subdentatus isn’t for every gardener – in fact, it’s only suitable for very specific situations. Here’s when you might want to consider it:

  • You’re creating a natural pond or water garden
  • You’re involved in wetland restoration projects
  • You want to support native aquatic ecosystems
  • You have a bog garden or permanently wet area

However, this plant probably isn’t right for you if you’re looking for showy flowers or dramatic visual impact above water. Its aesthetic appeal is subtle and primarily underwater.

Growing Conditions and Care

Successfully growing Potamogeton ×subdentatus requires recreating its natural wetland habitat:

  • Water requirements: Permanent standing water or submersed conditions
  • Light: Full sun to partial shade
  • Hardiness: Likely suitable for USDA zones 5-9 based on its natural range
  • Soil: Pond sediment or muddy substrates

Planting and Establishment Tips

Getting this aquatic native established requires some specialized techniques:

  • Plant directly in pond sediment or in submerged containers
  • Ensure water depth is appropriate for the species (typically shallow to moderate depths)
  • Allow time for establishment – aquatic plants can be slow to get going
  • Avoid chemical treatments in the water that might harm the plant

Role in Water Gardens and Landscapes

While Potamogeton ×subdentatus won’t be the star of your garden show, it serves important ecological functions in water features. It helps maintain water quality, provides habitat structure underwater, and contributes to the overall health of aquatic ecosystems. In naturalistic water gardens, it adds authentic native character even if its presence is more felt than seen.

Wildlife and Ecological Benefits

Though specific wildlife benefits aren’t well-documented for this particular species, pondweeds as a group typically support waterfowl, provide shelter for aquatic insects and fish, and contribute to the overall biodiversity of wetland communities. The inconspicuous flowers are likely wind-pollinated rather than providing significant pollinator resources.

The Bottom Line

Potamogeton ×subdentatus is definitely a niche plant – perfect for the right situation but completely inappropriate for most gardens. If you’re passionate about native aquatic plants and have the right water feature to support it, this species can add ecological authenticity to your landscape. Just remember that its beauty lies in its ecological function rather than its visual drama, making it a plant for the ecologically-minded water gardener rather than those seeking immediate aesthetic impact.

Wetland Status

The rule of seasoned gardeners and landscapers is to choose the "right plant for the right place" matching plants to their ideal growing conditions, so they'll thrive with less work and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection is. While tags list watering requirements, there's more to the story.

Knowing a plant's wetland status can simplify the process by revealing the interaction between plants, water, and soil. Surprisingly, many popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. Also, it helps you make smarter gardening choices and grow healthy plants with less care and feeding, saving you time, frustration, and money while producing an attractive garden with greater ecological benefits.

Regions
Status
Moisture Conditions

Atlantic and Gulf Coastal Plain

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Northcentral & Northeast

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Potamogeton ×subdentatus

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 ×subdentatus Hagstr. [illinoensis × perfoliatus]

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