North America Native Plant

Payson’s Wild Cabbage

Botanical name: Caulanthus simulans

USDA symbol: CASI5

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Payson’s Wild Cabbage: A Rare California Native Worth Preserving If you’re passionate about California native plants and love supporting rare species, Payson’s wild cabbage (Caulanthus simulans) might just capture your heart. This delicate annual herb represents one of nature’s more vulnerable treasures, quietly growing in select spots across California’s foothills ...

Rare plant alert!

Region: Conservation status by state

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

Payson’s Wild Cabbage: A Rare California Native Worth Preserving

If you’re passionate about California native plants and love supporting rare species, Payson’s wild cabbage (Caulanthus simulans) might just capture your heart. This delicate annual herb represents one of nature’s more vulnerable treasures, quietly growing in select spots across California’s foothills and valleys.

What Makes Payson’s Wild Cabbage Special?

Payson’s wild cabbage is an annual forb – essentially a soft-stemmed herbaceous plant that completes its entire life cycle in one growing season. Despite its common name suggesting a relationship to garden cabbage, this native California wildflower produces charming clusters of small, pale flowers that dance on slender stems in spring.

As a member of the mustard family, this plant showcases the classic four-petaled flowers that make identification easier for native plant enthusiasts. The blooms typically appear in white to pale yellow hues, creating a subtle but beautiful display during California’s wildflower season.

Where You’ll Find This California Native

Caulanthus simulans calls California home exclusively, with populations scattered throughout the state. This endemic species has adapted specifically to California’s unique climate and soil conditions, making it a true representative of the Golden State’s botanical heritage.

A Word of Caution: Rarity Matters

Here’s where things get serious. Payson’s wild cabbage carries a Global Conservation Status of S3, meaning it’s considered vulnerable to extinction. With only an estimated 21 to 100 occurrences and between 3,000 to 10,000 individuals remaining in the wild, this isn’t your typical backyard wildflower.

If you’re considering adding this species to your garden, responsible sourcing is absolutely critical. Never collect seeds or plants from wild populations – this could harm already fragile communities. Instead, seek out reputable native plant nurseries that propagate from ethically sourced material.

Growing Payson’s Wild Cabbage Successfully

Since this is an annual plant, Payson’s wild cabbage follows California’s natural rhythm of winter rains and summer drought. Here’s what you need to know:

Ideal Growing Conditions

  • Climate zones: USDA zones 8-10, matching California’s Mediterranean climate
  • Sunlight: Full sun to partial shade
  • Soil: Well-draining soils that don’t stay soggy
  • Water: Moderate water during spring growth, then allow to dry as summer approaches

Planting and Care Tips

The key to success with Payson’s wild cabbage lies in mimicking its natural growing cycle:

  • Direct seed in fall when winter rains begin
  • Provide moderate water through the spring growing season
  • Allow plants to set seed and naturally dry down in summer
  • Let dropped seeds remain for next year’s crop
  • Avoid over-watering, especially in summer months

Garden Role and Landscape Design

Payson’s wild cabbage works beautifully in specialized native California gardens, particularly those focused on rare or unusual species. Its delicate stature makes it perfect for:

  • Native wildflower meadows
  • Specialized rare plant collections
  • Educational gardens highlighting California’s botanical diversity
  • Naturalistic landscapes that celebrate local flora

Supporting Pollinators and Wildlife

Like many members of the mustard family, Payson’s wild cabbage provides nectar for small native bees and other pollinators during its spring blooming period. While we don’t have extensive data on its specific wildlife benefits, native plants generally support the intricate web of insects, birds, and other creatures that have co-evolved with them over thousands of years.

Should You Grow Payson’s Wild Cabbage?

The answer depends on your gardening goals and commitment level. If you’re:

  • Passionate about rare plant conservation
  • Dedicated to growing only California natives
  • Willing to source plants responsibly
  • Interested in supporting vulnerable species

Then Payson’s wild cabbage could be a meaningful addition to your garden. However, if you’re looking for a low-maintenance ground cover or showy display plant, you might want to consider more common California natives that can provide similar benefits without the conservation concerns.

Remember, growing rare plants is a responsibility as much as a privilege. By choosing to cultivate Payson’s wild cabbage with ethically sourced material, you’re not just adding beauty to your garden – you’re participating in conservation efforts that help ensure this vulnerable species continues to grace California’s landscapes for generations to come.

Payson’s Wild Cabbage

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

Caulanthus S. Watson - wild cabbage

Species

Caulanthus simulans Payson - Payson's wild cabbage

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