North America Native Plant

Whited’s Fissurewort

Botanical name: Halimolobos whitedii

USDA symbol: HAWH

Life cycle: perennial

Habit: forb

Native status: Native to Canada âš˜ Native to the lower 48 states  

Synonyms: Arabis whitedii Piper (ARWH2)   

Whited’s Fissurewort: A Rare Pacific Northwest Treasure Worth Protecting Have you ever heard of Whited’s fissurewort? Don’t worry if you haven’t – this little-known native plant is one of the Pacific Northwest’s best-kept secrets, and for good reason. With its tongue-twisting botanical name Halimolobos whitedii, this rare perennial deserves our ...

Rare plant alert!

Region: Conservation status by state

Status: S3?: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ 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 ⚘

Whited’s Fissurewort: A Rare Pacific Northwest Treasure Worth Protecting

Have you ever heard of Whited’s fissurewort? Don’t worry if you haven’t – this little-known native plant is one of the Pacific Northwest’s best-kept secrets, and for good reason. With its tongue-twisting botanical name Halimolobos whitedii, this rare perennial deserves our attention not for its garden potential, but for its conservation story.

What Is Whited’s Fissurewort?

Whited’s fissurewort is a native North American perennial forb – essentially a herbaceous flowering plant without woody stems. As a member of the mustard family (Brassicaceae), it shares characteristics with more familiar plants like wild mustard and rock cresses. In fact, it was once classified as Arabis whitedii, reflecting its close relationship to the rock cress genus.

This hardy little plant has adapted to some of the harshest conditions the Pacific Northwest can offer, thriving in rocky, mountainous terrain where few other plants dare to grow.

Where Does It Call Home?

Whited’s fissurewort has a remarkably small native range, found only in British Columbia, Canada, and Washington State. This limited distribution is part of what makes it so special – and so vulnerable. The plant appears to prefer alpine and subalpine environments, likely growing in rocky crevices and harsh mountain conditions.

A Plant That Needs Our Protection

Here’s where things get serious: Whited’s fissurewort has a Global Conservation Status of S3?, which indicates its rarity and uncertain conservation status. This means the plant is considered rare to uncommon, and there’s still uncertainty about its exact population status and threats.

If you’re considering adding this plant to your garden, please proceed with extreme caution and responsibility. Only source plants or seeds from reputable native plant nurseries that can verify their material wasn’t collected from wild populations. Better yet, consider supporting conservation efforts rather than cultivation.

Growing Conditions and Care

Based on its native habitat, Whited’s fissurewort likely thrives in:

  • Rocky, well-draining soils
  • Full sun to partial shade
  • Cold, harsh climates (probably USDA zones 3-7)
  • Alpine or subalpine conditions
  • Areas with significant temperature fluctuations

However, given its rarity, detailed cultivation information is scarce. This plant has evolved for very specific conditions that are difficult to replicate in typical garden settings.

Should You Grow Whited’s Fissurewort?

The short answer? Probably not. While it’s tempting to want to grow every native plant, Whited’s fissurewort is better left in its natural habitat or in the hands of conservation professionals. Its rarity means that every wild plant is precious, and unsuccessful cultivation attempts could waste valuable genetic material.

Instead, consider these alternatives that capture some of the same spirit:

  • Other native rock cresses (Arabis species)
  • Native mustard family plants suited to your area
  • Supporting conservation organizations working to protect rare Pacific Northwest flora

The Bigger Picture

Whited’s fissurewort reminds us that not every native plant is meant for our gardens. Sometimes, the best way to appreciate and support native flora is to protect their wild spaces and contribute to conservation efforts. This little mustard family member serves as an ambassador for the incredible diversity of plants that call the Pacific Northwest home – many of which remain understudied and vulnerable.

While you might not be planting Whited’s fissurewort in your garden anytime soon, learning about it connects us to the wild, rugged landscapes of the Pacific Northwest and reminds us why protecting these special places matters so much.

Whited’s Fissurewort

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Dilleniidae

Order

Capparales

Family

Brassicaceae Burnett - Mustard family

Genus

Halimolobos Tausch - fissurewort

Species

Halimolobos whitedii (Piper) Rollins - Whited's fissurewort

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