North America Native Plant

Vernal Pool Mousetail

Botanical name: Myosurus sessilis

USDA symbol: MYSE2

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Myosurus alopecuroides Greene (MYAL6)  âš˜  Myosurus minimus L. var. sessiliflorus (Huth) G.R. Campb. (MYMIS2)   

Vernal Pool Mousetail: A Rare Gem for Specialized Gardens Meet the vernal pool mousetail (Myosurus sessilis), one of nature’s most specialized and increasingly rare wildflowers. This tiny annual might not win any beauty contests, but for gardeners interested in creating authentic seasonal wetland habitats, it’s an irreplaceable piece of the ...

Rare plant alert!

Region: Conservation status by state

Status: S2: Status is uncertain but is somewhere between the following rankings: Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘

Vernal Pool Mousetail: A Rare Gem for Specialized Gardens

Meet the vernal pool mousetail (Myosurus sessilis), one of nature’s most specialized and increasingly rare wildflowers. This tiny annual might not win any beauty contests, but for gardeners interested in creating authentic seasonal wetland habitats, it’s an irreplaceable piece of the puzzle.

What Makes Vernal Pool Mousetail Special

Don’t let its modest appearance fool you – this little forb is a botanical marvel. Vernal pool mousetail gets its charming common name from its distinctive fruiting heads that elongate into slender, tail-like structures after the tiny white flowers fade. As an annual plant, it completes its entire life cycle in a single growing season, perfectly timed to the unique rhythm of seasonal pools.

This native wildflower belongs exclusively to California and Oregon, where it has adapted to one of the most challenging environments imaginable: vernal pools that flood in winter and spring, then completely dry out by summer.

A Plant with Endangered Status

Important Conservation Note: Vernal pool mousetail has a Global Conservation Status of S2, meaning it’s considered imperiled due to extreme rarity. With typically only 6 to 20 known occurrences and potentially fewer than 3,000 individuals remaining, this species is especially vulnerable to extinction.

If you’re considering growing this rare beauty, please only source seeds or plants from reputable native plant nurseries that practice ethical collection methods. Never collect from wild populations.

Why Grow Vernal Pool Mousetail?

This isn’t a plant for every gardener, but it’s perfect if you’re:

  • Creating a vernal pool garden or seasonal wetland habitat
  • Participating in native plant restoration projects
  • Designing specialized rain gardens that mimic natural flooding cycles
  • Supporting conservation efforts for rare native species

Its facultative wetland status means it thrives in areas that flood seasonally but can tolerate some drier conditions, making it ideal for gardens designed to capture and slowly release rainwater.

Growing Conditions and Care

Here’s where things get interesting – and challenging. Vernal pool mousetail isn’t your typical garden plant. It requires very specific conditions that can be tricky to replicate:

Climate Requirements: Hardy in USDA zones 8-10, matching its native California and Oregon range.

Seasonal Water Needs: This plant demands a precise wet-dry cycle. It needs standing water or consistently moist soil during winter and spring germination, followed by complete drying in summer.

Soil Preferences: Clay soils that hold water temporarily but eventually dry out completely work best. Standard garden soil with good drainage won’t cut it.

Sun Exposure: Full sun is essential for proper growth and flowering.

The Reality Check

Let’s be honest – successfully growing vernal pool mousetail requires serious commitment and very specific site conditions. Most home gardeners will find it nearly impossible to replicate the precise seasonal flooding and drying cycles this plant needs to thrive.

This makes it better suited for:

  • Specialized restoration projects
  • Botanical gardens with controlled water systems
  • Properties with natural seasonal wetlands
  • Advanced gardeners willing to install complex irrigation systems

Planting and Propagation Tips

If you’re determined to give it a try:

  • Start with seeds from reputable native plant sources
  • Plant in late fall before winter rains begin
  • Ensure your site can hold water for several months, then dry completely
  • Be patient – germination and growth follow natural seasonal patterns
  • Don’t expect quick results; this plant operates on nature’s timeline

The Bottom Line

Vernal pool mousetail represents the fascinating world of highly specialized native plants. While it’s not suitable for most traditional gardens, it offers dedicated conservationists and restoration enthusiasts a chance to support a truly rare and remarkable species.

If your heart is set on supporting vernal pool ecosystems but you lack the right conditions, consider visiting natural vernal pools during blooming season instead. Sometimes the best way to appreciate rare plants is to admire them in their native habitat while supporting the organizations working to protect these unique ecosystems.

For gardeners seeking easier native alternatives that provide similar seasonal interest, consider other native annuals that are more adaptable to typical garden conditions while still supporting local ecosystems.

Vernal Pool Mousetail

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Magnoliidae

Order

Ranunculales

Family

Ranunculaceae Juss. - Buttercup family

Genus

Myosurus L. - mousetail

Species

Myosurus sessilis S. Watson - vernal pool mousetail

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