North America Native Plant

California Winged Rockcress

Botanical name: Sibara rosulata

USDA symbol: SIRO

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

California Winged Rockcress: A Rare Native Worth Knowing About Meet California winged rockcress (Sibara rosulata), a little-known native annual that’s as elusive as it is intriguing. While you probably won’t find this plant at your local garden center, it’s worth learning about this rare California native – even if it’s ...

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 ⚘

California Winged Rockcress: A Rare Native Worth Knowing About

Meet California winged rockcress (Sibara rosulata), a little-known native annual that’s as elusive as it is intriguing. While you probably won’t find this plant at your local garden center, it’s worth learning about this rare California native – even if it’s not destined for your backyard flower bed.

What Makes California Winged Rockcress Special?

This petite annual belongs to the mustard family and grows as what botanists call a forb – essentially a non-woody flowering plant that completes its entire life cycle in a single growing season. Like a botanical shooting star, it appears, blooms, sets seed, and disappears until the next favorable year.

California winged rockcress is native to the lower 48 states, but don’t let that fool you into thinking it’s widespread. This plant calls only California home, and even there, it’s not exactly common. In fact, it carries a conservation status of S3?, which means scientists aren’t entirely sure how rare it is – and that’s rarely a good sign in the plant world.

Should You Grow California Winged Rockcress?

Here’s where things get honest: this probably isn’t the plant for most home gardeners, and here’s why:

  • It’s quite rare and difficult to source responsibly
  • As an annual, it won’t provide lasting structure in your garden
  • Limited information exists about its specific growing requirements
  • Its small size means it’s easily overlooked in typical landscape settings

However, if you’re a dedicated native plant enthusiast with experience growing rare California species, this plant might intrigue you. Just remember – if you do decide to try growing it, source your seeds or plants only from reputable native plant suppliers who can verify the material was ethically collected.

Growing Conditions and Care

While specific growing information for California winged rockcress is limited, we can make educated guesses based on its California origins and mustard family traits:

  • Climate: Likely thrives in USDA zones 8-10, matching California’s Mediterranean climate
  • Soil: Probably prefers well-draining soils, as most California natives do
  • Water: As an annual, likely adapted to seasonal rainfall patterns
  • Sun: Most rockcresses prefer full sun to partial shade

Because this is an annual plant, any growing efforts would need to focus on allowing it to complete its life cycle and set seed for future generations.

Wildlife and Pollinator Value

While specific data about California winged rockcress’s wildlife benefits isn’t well documented, plants in the mustard family typically provide nectar for small pollinators like bees and beneficial insects. However, given its rarity and small size, it’s not going to be a pollinator powerhouse in your garden.

The Bottom Line

California winged rockcress serves as a reminder that not every native plant is meant for cultivation. Sometimes, the best way to appreciate a rare species is to support conservation efforts and choose more readily available native alternatives for our gardens.

If you’re passionate about supporting California’s native flora, consider these more garden-friendly alternatives: California poppies, ceanothus species, or other well-established native wildflowers that can provide similar ecological benefits without the conservation concerns.

After all, the best native garden is one that thrives – and sometimes that means admiring the rare ones from afar while we nurture the natives that are ready to flourish in our care.

California Winged Rockcress

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

Sibara Greene - winged rockcress

Species

Sibara rosulata Rollins - California winged rockcress

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