North America Native Plant

Farnsworth’s Jewelflower

Botanical name: Streptanthus farnsworthianus

USDA symbol: STFA2

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Farnsworth’s Jewelflower: A Rare Gem for California Native Gardens Meet Farnsworth’s jewelflower (Streptanthus farnsworthianus), a delicate annual wildflower that’s as special as it is scarce. This California native is a true botanical treasure—literally. With its vulnerable conservation status, this little beauty deserves our attention and careful stewardship. What Makes Farnsworth’s ...

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 ⚘

Farnsworth’s Jewelflower: A Rare Gem for California Native Gardens

Meet Farnsworth’s jewelflower (Streptanthus farnsworthianus), a delicate annual wildflower that’s as special as it is scarce. This California native is a true botanical treasure—literally. With its vulnerable conservation status, this little beauty deserves our attention and careful stewardship.

What Makes Farnsworth’s Jewelflower Special?

Farnsworth’s jewelflower is an annual forb, meaning it completes its entire life cycle in one growing season and lacks woody stems. As a member of the mustard family, it produces clusters of small, cheerful yellow flowers that add a subtle charm to the landscape. Don’t expect a showy display—this plant’s beauty lies in its delicate, understated elegance.

What truly sets this species apart is its rarity. Farnsworth’s jewelflower has a Global Conservation Status of S3, meaning it’s considered vulnerable. With typically only 21 to 100 occurrences and between 3,000 to 10,000 individuals remaining, this plant is fighting for survival in its native habitat.

Where Does It Call Home?

This California endemic is found only within the Golden State’s borders, making it a true local specialty. Its limited distribution contributes to its vulnerable status, as the plant exists in just a handful of locations throughout California.

Should You Plant Farnsworth’s Jewelflower?

Here’s where things get important: if you’re considering adding this rare beauty to your garden, proceed with extreme caution and responsibility. Given its vulnerable status, you should only plant Farnsworth’s jewelflower if you can source seeds or plants through legitimate conservation programs or responsible native plant societies.

Never collect seeds or plants from wild populations—this could further threaten the species’ survival.

Perfect Garden Matches

If you can responsibly source this plant, Farnsworth’s jewelflower works wonderfully in:

  • Native California gardens focused on rare species conservation
  • Rock gardens with well-draining soils
  • Naturalistic landscapes that celebrate local flora
  • Educational gardens highlighting endangered plants

Growing Conditions and Care

Like many California natives, Farnsworth’s jewelflower appreciates:

  • Sunlight: Full sun to partial shade
  • Soil: Well-draining soils (essential for preventing root rot)
  • Water: Minimal irrigation once established—these plants are adapted to California’s dry conditions
  • Climate: USDA hardiness zones 8-10, matching California’s Mediterranean climate

Planting and Care Tips

Since this is an annual, timing is everything:

  • Direct seed in fall to allow natural winter stratification
  • Avoid overwatering—these plants prefer lean conditions
  • Allow plants to complete their lifecycle and drop seeds naturally
  • Consider companion planting with other California natives for a cohesive ecosystem

Benefits for Pollinators and Wildlife

Though small in stature, Farnsworth’s jewelflower plays its part in supporting local ecosystems. Its flowers attract small native bees and other pollinators that have co-evolved with California’s native mustard family plants. Every flower counts when supporting our native pollinator populations!

The Bottom Line

Farnsworth’s jewelflower represents both an opportunity and a responsibility. If you’re passionate about conservation and can source this plant responsibly, it’s a meaningful addition to a native California garden. However, this isn’t a plant for casual gardeners—it requires commitment to conservation ethics and appropriate sourcing.

Consider this species a gateway to learning more about California’s rare native plants and the importance of habitat conservation. Sometimes the most valuable plants in our gardens are the ones that teach us about stewardship and the delicate balance of our natural world.

Farnsworth’s Jewelflower

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

Streptanthus Nutt. - twistflower

Species

Streptanthus farnsworthianus J.T. Howell - Farnsworth's jewelflower

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