North America Native Plant

Shieldplant

Botanical name: Streptanthus tortuosus var. suffrutescens

USDA symbol: STTOS

Life cycle: biennial

Habit: subshrub

Native status: Native to the lower 48 states  

Shieldplant: A Unique California Native for Specialty Gardens If you’re looking to add a truly distinctive California native to your garden, shieldplant (Streptanthus tortuosus var. suffrutescens) might just be the quirky addition you never knew you needed. This fascinating member of the mustard family brings both botanical interest and ecological ...

Rare plant alert!

Region: Conservation status by state

Status: S5T3?: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ Subspecies or variety is 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. ⚘ Secure: At very low or no risk of extinction in the jurisdiction due to a very extensive range, abundant populations or occurrences, with little to no concern from declines or threats. ⚘

Shieldplant: A Unique California Native for Specialty Gardens

If you’re looking to add a truly distinctive California native to your garden, shieldplant (Streptanthus tortuosus var. suffrutescens) might just be the quirky addition you never knew you needed. This fascinating member of the mustard family brings both botanical interest and ecological value to the right garden setting.

What Makes Shieldplant Special?

Shieldplant is a forb or herbaceous plant that can live as an annual, biennial, or perennial depending on growing conditions. What sets it apart from other wildflowers is its unique twisted seed pods and distinctive flowers that range from yellow to purple. As a member of the Streptanthus genus, it’s perfectly adapted to California’s challenging growing conditions.

Where Does Shieldplant Come From?

This plant is a true California endemic, meaning it naturally occurs only in the Golden State. It’s particularly fond of serpentine soils – those mineral-rich, challenging growing conditions that many plants can’t handle but that create unique plant communities throughout California.

Why Grow Shieldplant in Your Garden?

Here are some compelling reasons to consider this native beauty:

  • Authentic California gardening: Support local ecosystems with a truly native species
  • Pollinator magnet: Attracts native bees and butterflies that have co-evolved with this plant
  • Unique aesthetic: The twisted seed pods and variable flower colors add visual interest
  • Low maintenance: Once established, requires minimal care and water
  • Conversation starter: Few gardeners grow this unusual native

Important Conservation Note

Shieldplant has a conservation status that suggests it may be of some conservation concern. If you decide to grow this plant, please ensure you source it responsibly from reputable native plant nurseries rather than collecting from the wild. This helps preserve wild populations while allowing you to enjoy this special plant in your garden.

Growing Conditions and Care

Shieldplant thrives in USDA hardiness zones 8-10, making it suitable for most of California and similar Mediterranean climates. Here’s what it needs to succeed:

  • Soil: Well-draining, rocky, or sandy soils; excellent drainage is crucial
  • Sun exposure: Full sun
  • Water: Minimal water once established; avoid overwatering
  • Soil type: Tolerates poor soils, including serpentine

Perfect Garden Settings

This isn’t a plant for every garden, but it shines in the right setting:

  • Rock gardens: Perfect for well-draining, rocky environments
  • Native plant gardens: Ideal for authentic California landscapes
  • Specialty collections: Great for gardeners who love unique natives
  • Serpentine gardens: Excellent choice for challenging serpentine soils

Planting and Care Tips

Success with shieldplant comes down to mimicking its natural habitat:

  • Plant in fall for spring blooms
  • Ensure excellent drainage – this plant hates wet feet
  • Start with small plants from nurseries rather than seeds
  • Water sparingly once established
  • Avoid fertilizing – it prefers lean soils
  • Allow seed pods to mature if you want self-seeding

The Bottom Line

Shieldplant isn’t for every gardener or every garden, but for those interested in authentic California native gardening, it offers something truly special. Its unique appearance, pollinator benefits, and adaptation to challenging conditions make it a rewarding choice for the right setting. Just remember to source it responsibly and provide the well-draining conditions it craves.

If you’re ready to try something different in your native garden, shieldplant might be exactly the distinctive touch you’re looking for. Your local pollinators will thank you, and you’ll have bragging rights to one of California’s more unusual native beauties.

Shieldplant

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 tortuosus Kellogg - shieldplant

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