North America Native Plant

Grimy Mousetail

Botanical name: Ivesia rhypara var. rhypara

USDA symbol: IVRHR

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Grimy Mousetail: A Rare Native Gem for Specialized Gardens Meet grimy mousetail (Ivesia rhypara var. rhypara), a charming yet uncommon native perennial that’s definitely not your average garden plant. Don’t let the quirky name fool you – this little Great Basin native has a unique appeal that makes it a ...

Rare plant alert!

Region: Conservation status by state

Status: S2T2: 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) ⚘ Subspecies or variety is 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) ⚘

Grimy Mousetail: A Rare Native Gem for Specialized Gardens

Meet grimy mousetail (Ivesia rhypara var. rhypara), a charming yet uncommon native perennial that’s definitely not your average garden plant. Don’t let the quirky name fool you – this little Great Basin native has a unique appeal that makes it a treasure for dedicated native plant enthusiasts and conservation-minded gardeners.

A Rare Beauty Worth Protecting

Before we dive into growing this special plant, there’s something important you should know: grimy mousetail is considered rare, with a Global Conservation Status of S2T2. This means it has limited distribution and faces potential threats in its native habitat. If you’re interested in growing this plant, it’s crucial to source it only from reputable native plant nurseries that propagate from responsibly collected seed or divisions – never collect from wild populations.

Where It Calls Home

Grimy mousetail is a true native of the American West, naturally occurring in Nevada and Oregon within the Great Basin region. This perennial forb has adapted to the challenging conditions of this high desert ecosystem, making it quite different from typical garden plants.

What Makes It Special

As a herbaceous perennial forb, grimy mousetail forms low-growing rosettes of compound leaves that hug the ground. During its blooming period, it produces clusters of small, cream-colored to white flowers that may look modest but serve an important role in supporting native pollinators like small bees and other beneficial insects.

The plant’s compact, ground-hugging form makes it an interesting addition to rock gardens or specialized native plant collections, where its subtle beauty can be appreciated up close.

Growing Conditions and Care

If you’re considering adding grimy mousetail to your garden, be prepared for a plant with very specific needs:

  • Drainage is everything: This plant absolutely requires well-draining, rocky or sandy soil – think desert conditions
  • Water sparingly: Once established, it’s extremely drought tolerant and actually prefers dry conditions
  • Sun exposure: Provide full sun to partial shade
  • Climate zones: Best suited for USDA zones 4-8, matching its native range
  • Soil type: Sandy, gravelly, or rocky soils with minimal organic matter

Is Grimy Mousetail Right for Your Garden?

This plant isn’t for everyone, and that’s perfectly okay! Grimy mousetail is best suited for gardeners who:

  • Have experience with native plants and challenging growing conditions
  • Want to support local ecosystems and rare plant conservation
  • Enjoy rock gardens or xerophytic plant collections
  • Live in the western United States where the climate naturally supports it
  • Have access to responsibly sourced plants or seeds

Planting and Care Tips

Success with grimy mousetail requires mimicking its native habitat:

  • Soil preparation: Create a well-draining mix with sand, gravel, and minimal organic matter
  • Planting: Spring is typically the best time to plant, allowing the root system to establish before winter
  • Watering: Water occasionally during the first growing season, then rely on natural precipitation
  • Maintenance: Minimal maintenance required – avoid fertilizers and excessive moisture
  • Winter care: Generally hardy in its native range, but protect from excessive winter moisture

Supporting Conservation Through Gardening

By choosing to grow grimy mousetail from responsibly sourced material, you’re participating in plant conservation efforts. This rare native provides habitat for specialized pollinators and helps maintain genetic diversity outside of wild populations. Just remember – only purchase from reputable sources that can verify their plants were ethically propagated, not collected from wild populations.

While grimy mousetail might not be the flashiest addition to your garden, it represents something special: a connection to the unique ecosystems of the American West and an opportunity to support conservation through thoughtful gardening choices.

Grimy Mousetail

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Rosidae

Order

Rosales

Family

Rosaceae Juss. - Rose family

Genus

Ivesia Torr. & A. Gray - mousetail

Species

Ivesia rhypara Ertter & Reveal - grimy mousetail

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