North America Native Plant

Ostler’s Mousetail

Botanical name: Ivesia shockleyi var. ostleri

USDA symbol: IVSHO

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Ostler’s Mousetail: A Rare Utah Native Worth Knowing About Meet Ostler’s mousetail (Ivesia shockleyi var. ostleri), one of Utah’s botanical hidden gems that most gardeners have never heard of. This little-known native plant represents the kind of specialized flora that makes our local ecosystems so unique and irreplaceable. What Exactly ...

Rare plant alert!

Region: Conservation status by state

Status: S3S4T1: Status is uncertain but is somewhere between the following rankings: Subspecies or variety is critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘ Vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals ⚘ Apparently Secure: Uncommon but not rare, and usually widespread. Possibly cause for longterm concern. Typically more than 100 occurrences in the state or more than 10,000 individuals ⚘

Ostler’s Mousetail: A Rare Utah Native Worth Knowing About

Meet Ostler’s mousetail (Ivesia shockleyi var. ostleri), one of Utah’s botanical hidden gems that most gardeners have never heard of. This little-known native plant represents the kind of specialized flora that makes our local ecosystems so unique and irreplaceable.

What Exactly Is Ostler’s Mousetail?

Ostler’s mousetail is a perennial forb—essentially a non-woody flowering plant that comes back year after year. As a member of the Ivesia genus, it’s part of the rose family, though you might not immediately recognize the family resemblance. This plant lacks any significant woody tissue and keeps its growing points at or below ground level, helping it survive harsh conditions.

Where Does It Call Home?

This variety is native to the lower 48 United States, but you won’t find it just anywhere. Ostler’s mousetail is endemic to Utah, meaning it naturally occurs nowhere else on Earth. This makes it a true Utah original—a plant that evolved specifically to thrive in the unique conditions found within the state’s borders.

Why Should Gardeners Care About This Rare Plant?

Here’s where things get interesting (and important): Ostler’s mousetail has a Global Conservation Status of S3S4T1, indicating it’s quite rare. While the exact meaning of this designation isn’t entirely clear from available data, any plant with such a specific conservation status deserves our attention and respect.

For gardeners, this rarity presents both an opportunity and a responsibility. If you’re passionate about growing truly unique, locally-adapted plants, rare natives like this one represent the ultimate in garden authenticity. However, with rarity comes the crucial need for responsible sourcing.

The Reality Check for Home Gardeners

Let’s be honest—information about growing Ostler’s mousetail is practically nonexistent in horticultural literature. This isn’t surprising given its rarity and specialized habitat requirements. Most rare endemic plants have very specific growing conditions that can be challenging to replicate in home gardens.

If you’re determined to grow this species, here are the essential considerations:

  • Only obtain plants or seeds from reputable native plant nurseries that practice ethical collection
  • Never collect from wild populations—this could harm already vulnerable populations
  • Research Utah’s specific climate and soil conditions where this plant naturally occurs
  • Be prepared for a potentially challenging growing experience with limited guidance available

Better Alternatives for Most Gardeners

Unless you’re a specialist in rare plant cultivation or involved in conservation efforts, you might want to consider other Utah native plants that are more readily available and better documented for garden use. The Ivesia genus includes other species that might be more suitable for home cultivation while still providing that unique, locally-native appeal.

The Bigger Picture

Plants like Ostler’s mousetail remind us that our native flora includes incredibly specialized species that have evolved to fill very specific ecological niches. Even if we can’t all grow them in our gardens, knowing about them helps us appreciate the complexity and wonder of our local ecosystems.

By supporting habitat conservation and choosing other native plants for our gardens, we can help protect the natural communities where rare species like this one continue to thrive in the wild—which is ultimately where they belong.

The Bottom Line

Ostler’s mousetail represents the fascinating diversity of Utah’s native flora, but it’s probably not destined for most home gardens. Its rarity makes it more of a conservation priority than a gardening opportunity. If this unique plant has caught your interest, consider it an invitation to explore the wonderful world of Utah native plants—there are plenty of other species that are both garden-worthy and more readily available for home cultivation.

Ostler’s 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 shockleyi S. Watson - sky mousetail

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