North America Native Plant

San Luis Yellowcress

Botanical name: Rorippa coloradensis

USDA symbol: ROCO2

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

San Luis Yellowcress: A Ghost from Colorado’s Past Meet San Luis yellowcress (Rorippa coloradensis), a plant that might just be the botanical equivalent of a ghost story. This little perennial herb once called Colorado home, but today it exists more in memory than in meadow. If you’re thinking about adding ...

Rare plant alert!

Region: Conservation status by state

Status: SH: Status is uncertain but is somewhere between the following rankings: Possibly Extinct: Known only from historical occurrences. Still some hope of rediscovery ⚘

San Luis Yellowcress: A Ghost from Colorado’s Past

Meet San Luis yellowcress (Rorippa coloradensis), a plant that might just be the botanical equivalent of a ghost story. This little perennial herb once called Colorado home, but today it exists more in memory than in meadow. If you’re thinking about adding this native beauty to your garden, well, you might want to sit down for this one.

A Plant on the Edge of Forever

San Luis yellowcress holds the sobering conservation status of SH – which stands for Possibly Extirpated. In plain English? This means scientists know it existed historically, but haven’t seen hide nor hair (or leaf nor flower) of it in recent years. There’s still a glimmer of hope that someone might rediscover it tucked away in some forgotten corner of Colorado, but for now, this little yellowcress is playing the ultimate game of hide-and-seek.

Where It Once Roamed

This native Colorado species had an extremely limited range, known only from the San Luis Valley region. As a member of the lower 48 states’ native flora, it represents part of our natural heritage that we may have already lost.

What We Know (And What We’ve Lost)

San Luis yellowcress was a perennial forb – basically a soft-stemmed, non-woody plant that would come back year after year. Like other members of the mustard family, it likely produced small yellow flowers that would have provided nectar for local pollinators. As a forb, it would have been an important part of the ground layer in its native ecosystem, helping to create the complex tapestry of plant life that supports wildlife.

Why You Can’t (And Shouldn’t) Grow It

Here’s the thing about possibly extinct plants – you can’t exactly pop down to your local nursery and pick one up. But even if you could somehow find seeds or plants claiming to be San Luis yellowcress, you absolutely shouldn’t plant them without verification from botanical experts and proper conservation protocols.

Here’s why:

  • Any remaining genetic material is precious and should be in the hands of conservation professionals
  • Unverified plants could be mislabeled, spreading confusion about this rare species
  • If any populations do still exist, they need protection in their natural habitat, not cultivation in gardens

What You Can Do Instead

While you can’t grow San Luis yellowcress, you can still honor its memory and support conservation efforts:

  • Plant other native Colorado wildflowers that provide similar ecological benefits
  • Support local botanical gardens and conservation organizations working to protect rare plants
  • Keep your eyes peeled during Colorado hikes – you never know if you might be the one to rediscover this lost species
  • Choose native alternatives from the mustard family that are still thriving

A Lesson in Conservation

San Luis yellowcress serves as a poignant reminder that native plants aren’t guaranteed to stick around forever. Climate change, habitat loss, and human activities can push even well-adapted native species to the brink. Every native plant in your garden is a small victory for biodiversity and a hedge against future losses.

While we may not be able to grow San Luis yellowcress, we can learn from its story. By choosing native plants that are still with us, creating habitat for wildlife, and supporting conservation efforts, we can help ensure that future gardeners won’t be reading about their favorite plants in the past tense.

Sometimes the most important gardening lesson isn’t about what to plant, but about what we stand to lose – and what we can still save.

San Luis 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 coloradensis R. Stuckey - San Luis yellowcress

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