North America Native Plant

Triangle Waterfern

Botanical name: Ceratopteris richardii

USDA symbol: CERI2

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states âš˜ Native to Puerto Rico  

Triangle Waterfern: A Delicate Native Beauty for Your Water Garden If you’re dreaming of adding some elegant, lacy foliage to your water garden or bog area, let me introduce you to the triangle waterfern (Ceratopteris richardii). This charming native fern brings a touch of tropical sophistication to wetland gardens across ...

Triangle Waterfern: A Delicate Native Beauty for Your Water Garden

If you’re dreaming of adding some elegant, lacy foliage to your water garden or bog area, let me introduce you to the triangle waterfern (Ceratopteris richardii). This charming native fern brings a touch of tropical sophistication to wetland gardens across the southeastern United States.

What Makes Triangle Waterfern Special?

Triangle waterfern is an annual fern that lives up to its name with distinctively triangular fronds that create a delicate, fine-textured appearance. As a forb (a non-woody vascular plant), it offers soft, bright green foliage that contrasts beautifully with broader-leaved water plants. Don’t let its delicate appearance fool you though – this little beauty is perfectly adapted to aquatic life!

Where You’ll Find It Growing Wild

This native gem naturally calls home to Alabama, Louisiana, and Puerto Rico, where it thrives in wetland environments. As an obligate wetland plant across all its native regions – including the Atlantic and Gulf Coastal Plain, Caribbean, and Eastern Mountains and Piedmont – triangle waterfern almost always occurs in consistently wet conditions.

Perfect Spots in Your Garden

Triangle waterfern is your go-to choice for:

  • Water garden edges and pond margins
  • Bog gardens and rain gardens
  • Naturalistic wetland plantings
  • Aquatic container gardens
  • Areas with consistent moisture or standing water

Its fine texture makes it an excellent companion for bold-leaved water plants, creating lovely contrasts in foliage size and shape.

Growing Conditions That Make It Happy

Here’s where triangle waterfern gets a bit demanding – and rightfully so! This moisture-loving native needs:

  • Consistently wet to aquatic conditions (it can even float!)
  • Full to partial sun exposure
  • Rich, organic soil or aquatic growing medium
  • USDA hardiness zones 8-11 (it’s not frost-hardy)
  • Warm temperatures year-round

Planting and Care Tips

Since triangle waterfern is an annual, you’ll need to replant it each year in most climates. Here’s how to keep it thriving:

  • Plant in spring after the last frost date
  • Ensure constant moisture – never let it dry out
  • Consider growing it as a floating aquatic plant or in saturated bog soil
  • In colder zones, treat it as an annual or bring containers indoors
  • Provide some protection from intense afternoon sun in hotter climates

Wildlife and Ecosystem Benefits

While triangle waterfern doesn’t produce flowers to attract pollinators (ferns reproduce through spores, not flowers!), it still contributes to wetland ecosystem health by providing habitat structure and helping with water filtration in aquatic environments.

Is Triangle Waterfern Right for Your Garden?

Choose triangle waterfern if you have a water feature, bog garden, or consistently moist area and live in zones 8-11. Its delicate beauty and native status make it a wonderful addition to naturalistic water gardens. However, if you’re looking for a low-maintenance, drought-tolerant plant, this probably isn’t your match – triangle waterfern needs consistent moisture to thrive.

For gardeners in its native range, triangle waterfern offers a chance to support local ecosystems while adding unique texture to water gardens. Just remember: happy triangle waterfern equals wet triangle waterfern!

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

Caribbean

OBL

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

Eastern Mountains and Piedmont

OBL

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

Triangle Waterfern

Classification

Group

Fern

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision
Division

Pteridophyta - Ferns

Subdivision
Class

Filicopsida

Subclass
Order

Polypodiales

Family

Parkeriaceae Hook. - Water Fern family

Genus

Ceratopteris Brongn. - antlerfern

Species

Ceratopteris richardii Brongn. - triangle waterfern

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