North America Non-native Plant

Mackenzie River Yellowcress

Botanical name: Rorippa crystallina

USDA symbol: ROCR2

Life cycle: perennial

Habit: forb

Native status: Non-native, reproduces and persists in the wild in Canada  

Synonyms: Nasturtium crystallinum (Rollins) Mulligan (NACR2)   

MacKenzie River Yellowcress: A Rare Arctic Perennial Meet MacKenzie River yellowcress (Rorippa crystallina), a little-known perennial that’s as mysterious as its remote northern habitat. This uncommon member of the mustard family has managed to fly under the radar of most gardeners, and for good reason – it’s not your typical ...

MacKenzie River Yellowcress: A Rare Arctic Perennial

Meet MacKenzie River yellowcress (Rorippa crystallina), a little-known perennial that’s as mysterious as its remote northern habitat. This uncommon member of the mustard family has managed to fly under the radar of most gardeners, and for good reason – it’s not your typical backyard bloomer.

What Is MacKenzie River Yellowcress?

MacKenzie River yellowcress is a perennial forb, meaning it’s a non-woody plant that comes back year after year. Like other members of its family, it lacks the thick, woody stems you’d find on shrubs or trees, instead producing softer, herbaceous growth. You might also see this plant listed under its scientific synonym, Nasturtium crystallinum.

As a forb, this plant keeps its growing points (called perennating buds) at or below ground level, helping it survive harsh conditions by staying protected during winter months.

Where Does It Grow?

Here’s where things get interesting – and a bit concerning for most gardeners. MacKenzie River yellowcress is considered non-native to Canada, despite being found in the Northwest Territories. This suggests it’s an introduced species that has managed to establish itself and reproduce without human assistance in these remote northern regions.

The fact that it’s thriving in such a specific, harsh climate zone tells us this isn’t a plant that’s likely to adapt well to most garden conditions further south.

Should You Grow MacKenzie River Yellowcress?

Here’s the honest truth: probably not. While we don’t have definitive information about its invasive potential, the combination of being non-native and having limited growing information makes it a risky choice for home gardens. Plus, sourcing this plant would be extremely difficult, if not impossible, for most gardeners.

Better Native Alternatives

Instead of hunting for this elusive yellowcress, consider these native alternatives that offer similar or better benefits:

  • Wild mustard species native to your region – Check with local native plant societies
  • Native watercress varieties – If you’re drawn to the cress connection
  • Regional wildflowers – Support local ecosystems with plants adapted to your specific climate

The Mystery Factor

What makes MacKenzie River yellowcress particularly intriguing is how little we know about it. Information about its growing conditions, wildlife benefits, and garden suitability is practically non-existent in mainstream horticultural sources. This lack of data suggests it’s either extremely specialized in its requirements or simply hasn’t been studied extensively for garden use.

The Bottom Line

While MacKenzie River yellowcress might sound exotic and appealing, it’s not a practical choice for most gardens. The combination of its non-native status, extremely limited range, and lack of cultivation information makes it better left in its natural habitat in the far north.

Your garden – and local ecosystem – will be much better served by choosing well-documented native plants that support local wildlife and are adapted to your growing conditions. Save your energy for plants that will truly thrive in your space while contributing to your local environment.

Mackenzie River Yellowcress

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

Rorippa Scop. - yellowcress

Species

Rorippa crystallina Rollins, nom. inq. - MacKenzie River yellowcress

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