North America Native Plant

Pacific Waterclover

Botanical name: Marsilea oligospora

USDA symbol: MAOL3

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Marsilea vestiva Hook. & Grev. var. oligospora (Goodding) Dorn (MAVEO)   

Pacific Waterclover: The Native Aquatic Fern That Looks Like a Four-Leaf Clover If you’ve ever wished you could grow lucky four-leaf clovers in your water garden, Pacific waterclover might just be the plant of your dreams! Despite its common name, this charming native isn’t actually a clover at all—it’s a ...

Pacific Waterclover: The Native Aquatic Fern That Looks Like a Four-Leaf Clover

If you’ve ever wished you could grow lucky four-leaf clovers in your water garden, Pacific waterclover might just be the plant of your dreams! Despite its common name, this charming native isn’t actually a clover at all—it’s a unique aquatic fern with distinctive four-part leaves that create magical carpets across shallow waters.

What Exactly Is Pacific Waterclover?

Pacific waterclover (Marsilea oligospora) is a perennial aquatic fern native to the western United States. Unlike typical ferns with their feathery fronds, this fascinating plant produces leaves that look remarkably like four-leaf clovers, complete with the classic heart-shaped leaflets. As a forb—meaning it’s an herbaceous plant without woody stems—it spreads along pond edges and seasonal wetlands, creating distinctive floating or emergent carpets.

Where Does It Grow Naturally?

This native beauty calls the American West home, naturally occurring across eight states: California, Idaho, Montana, Nevada, Oregon, Utah, Washington, and Wyoming. You’ll find it thriving in seasonal wetlands, vernal pools, pond margins, and slow-moving streams throughout these regions.

Why Consider Pacific Waterclover for Your Garden?

There are several compelling reasons to include this unique native in your landscape:

  • Native authenticity: Supporting local ecosystems by choosing indigenous plants
  • Unique appearance: The four-leaf clover look adds whimsical charm to water features
  • Low maintenance: Once established, it requires minimal care
  • Habitat creation: Provides shelter and habitat structure in aquatic environments
  • Seasonal interest: Adapts beautifully to changing water levels throughout the year

Perfect Garden Settings

Pacific waterclover shines in specialized garden environments:

  • Native water gardens and natural ponds
  • Rain gardens and bioswales
  • Seasonal wetland restoration projects
  • Bog gardens and marsh replications
  • Wildlife habitat gardens near water features

Growing Conditions and Care

As an obligate wetland plant, Pacific waterclover has very specific needs that make it unsuitable for typical garden beds. Here’s what it requires:

Essential Growing Requirements:

  • Water: Consistently moist to wet soils; tolerates seasonal flooding and partial drying
  • Light: Full sun to partial shade
  • Soil: Muddy, clay, or sandy substrates in aquatic environments
  • Hardiness: Thrives in USDA zones 4-9
  • pH: Adaptable to various water pH levels

Planting and Care Tips:

  • Plant in spring when water temperatures begin to warm
  • Place in shallow water areas (6 inches deep or less)
  • Allow for seasonal water level fluctuations
  • Minimal fertilization needed—it adapts to nutrient-poor conditions
  • Naturally spreads via underground rhizomes
  • No pruning required; dies back naturally in winter

Important Considerations

Before adding Pacific waterclover to your garden, keep these factors in mind:

  • Specialized habitat: Only suitable for water gardens and consistently wet areas
  • Seasonal appearance: Dies back in winter, returning in spring
  • Spreading nature: Will naturalize and spread in suitable conditions
  • Limited availability: May be challenging to source from typical nurseries

Wildlife and Ecological Benefits

While Pacific waterclover doesn’t produce flowers to attract pollinators (being a fern, it reproduces via spores), it still contributes significantly to wetland ecosystems. The dense mats provide important habitat structure for aquatic insects, amphibians, and small fish, while the unique leaf structure offers shelter and breeding areas for various wetland wildlife.

Is Pacific Waterclover Right for Your Garden?

Pacific waterclover is an excellent choice for gardeners with appropriate water features who want to incorporate authentic native plants into their landscapes. However, it’s definitely a specialty plant—if you don’t have a pond, bog garden, or rain garden with standing water, this isn’t the plant for you.

For those lucky enough to have suitable aquatic habitats, Pacific waterclover offers a unique opportunity to grow something truly special—a native fern that brings both ecological value and whimsical beauty to western water gardens. Just remember to source your plants responsibly from reputable native plant suppliers to ensure you’re getting authentic, locally appropriate genetic material.

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

Arid West

OBL

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

Atlantic and Gulf Coastal Plain

OBL

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

Western Mountains, Valleys, and Coast

OBL

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

Pacific Waterclover

Classification

Group

Fern

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision
Division

Pteridophyta - Ferns

Subdivision
Class

Filicopsida

Subclass
Order

Hydropteridales

Family

Marsileaceae Mirb. - Water-clover family

Genus

Marsilea L. - waterclover

Species

Marsilea oligospora Goodding - Pacific waterclover

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