Native Plants

Crandall’s Rockcress

Arabis crandallii

USDA symbol: ARCR5

perennial forb

Lower 48 states: native

Meet Crandall’s rockcress (Arabis crandallii), a little-known perennial wildflower that’s as rare as it is charming. This delicate native plant might not be on every gardener’s wishlist, but for those passionate about conservation and supporting our most vulnerable species, it represents something truly special. Also known scientifically as Boechera crandallii, ...

Crandall’s Rockcress may be listed as rare in your area.
Global Conservation Status

Status: S2 | Imperiled: Extremely rare. Typically 6 to 20 occurrences or 1,000 to 3,000 remaining individuals.

Crandall’s Rockcress: A Rare Rocky Mountain Treasure Worth Protecting

Meet Crandall’s rockcress (Arabis crandallii), a little-known perennial wildflower that’s as rare as it is charming. This delicate native plant might not be on every gardener’s wishlist, but for those passionate about conservation and supporting our most vulnerable species, it represents something truly special.

What Makes Crandall’s Rockcress Special?

Also known scientifically as Boechera crandallii, this petite perennial belongs to the mustard family and embodies the tough-yet-tender spirit of Rocky Mountain flora. As a forb (that’s garden-speak for a non-woody flowering plant), it lacks the dramatic presence of shrubs or trees but makes up for it with quiet resilience and ecological importance.

What truly sets Crandall’s rockcress apart is its rarity. This plant carries a Global Conservation Status of S2, meaning it’s considered Imperiled. With typically only 6 to 20 known populations and fewer than 3,000 individual plants remaining in the wild, every single specimen matters.

Where Does It Call Home?

Crandall’s rockcress is a true child of the American West, native to just two states: Colorado and Wyoming. This limited range tells us everything we need to know about its specific habitat requirements and why it’s become so rare.

  • Species observed
  • No observations

Should You Grow Crandall’s Rockcress?

Here’s where things get interesting. If you’re passionate about native plant conservation and have experience with challenging alpine species, Crandall’s rockcress could be a meaningful addition to your garden. However, there’s a big but coming.

Important Conservation Note: Due to its imperiled status, you should only consider growing this plant if you can source it from reputable native plant specialists who propagate it responsibly. Never collect seeds or plants from wild populations – doing so could push this species closer to extinction.

Garden Role and Design Potential

If you do manage to source this rare beauty responsibly, Crandall’s rockcress would be best suited for:

  • Specialized rock gardens designed for alpine plants
  • Conservation-focused native plant collections
  • Educational gardens highlighting rare regional flora
  • Xeriscaping projects emphasizing local biodiversity

This isn’t a plant for casual landscaping or mass plantings. Think of it more as a living piece of natural heritage that deserves special attention and care.

Growing Conditions and Care

Based on its native Colorado and Wyoming habitat, Crandall’s rockcress likely thrives in:

  • Well-draining, rocky or gravelly soils
  • Full sun to partial shade conditions
  • Cooler mountain climates (probably hardy in USDA zones 3-6)
  • Low-moisture environments once established

Like many alpine plants, it probably appreciates good drainage year-round and may benefit from protection during harsh winters, despite its cold hardiness.

Wildlife and Pollinator Benefits

While specific wildlife benefits aren’t well-documented due to its rarity, rockcress species typically provide early-season nectar for small pollinators, including native bees and beneficial insects. In its natural habitat, it likely plays a small but important role in supporting local ecosystem health.

The Bottom Line

Crandall’s rockcress represents both an opportunity and a responsibility. For most gardeners, supporting more common native plants from your region will provide greater ecological bang for your buck. But if you’re an experienced native plant gardener with a passion for conservation, growing this species from responsibly sourced material could contribute to its long-term survival.

Remember: every rare plant garden represents a potential seed bank for the future. Just make sure you’re part of the solution, not part of the problem, by sourcing plants ethically and never disturbing wild populations.

Sometimes the most rewarding plants to grow are the ones that need us most.

Arabis crandallii is also known as...

Often we refer to plants by their common names. When shopping for plants the scientific name is the best way to positively identify the plant species you desire. But some plants have more than one name! While it doesn't happen often, nurseries might display one name while you're searching for another. Arabis crandallii is also known as:

Boechera crandallii | USDA symbol: BOCR3

Why do some plants have more than one name? Over time plant species may be renamed for a few reasons:

  1. Botanists in different regions named the same plant without knowing it had already been classified.
  2. A species was reclassified after scientific advances in, for example, DNA analysis.
  3. Slight variations within a species are sometimes mistakenly identified as entirely new species.

Classification

Group: Dicot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Subdivision: N/A
Class: Magnoliopsida - Dicotyledons
Subclass: Dilleniidae
Order: Capparales
Family: Brassicaceae Burnett - Mustard family
Genus: Arabis L. - rockcress

Species: Arabis crandallii B.L. Rob. - Crandall's rockcress

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