North America Native Plant

Shieldplant

Botanical name: Streptanthus tortuosus var. tortuosus

USDA symbol: STTOT2

Life cycle: biennial

Habit: subshrub

Native status: Native to the lower 48 states  

Shieldplant: A Quirky Native Beauty for West Coast Gardens Meet the shieldplant (Streptanthus tortuosus var. tortuosus), a delightfully unconventional native wildflower that’s sure to spark conversations in your garden. This isn’t your typical pretty-in-pink garden darling—shieldplant marches to the beat of its own drum with twisted stems and inflated purple ...

Shieldplant: A Quirky Native Beauty for West Coast Gardens

Meet the shieldplant (Streptanthus tortuosus var. tortuosus), a delightfully unconventional native wildflower that’s sure to spark conversations in your garden. This isn’t your typical pretty-in-pink garden darling—shieldplant marches to the beat of its own drum with twisted stems and inflated purple flowers that look like tiny shields, hence the name!

What Makes Shieldplant Special?

Shieldplant is a true West Coast native, calling California and Oregon home. As a forb herb, it’s a non-woody plant that can live as an annual, biennial, or perennial depending on conditions. What really sets this plant apart is its unique flower structure—small purple to violet blooms with inflated sepals that create an almost balloon-like appearance, paired with characteristically twisted stems that give the plant its scientific name tortuosus.

Where Does Shieldplant Grow?

This native beauty naturally occurs throughout California and Oregon, particularly thriving in the mountainous and foothill regions of these states. If you’re gardening in the western United States, you’re in luck—this plant has evolved specifically for your climate!

Why Grow Shieldplant in Your Garden?

Here are several compelling reasons to give shieldplant a spot in your landscape:

  • Native credentials: Supporting local ecosystems by growing plants that belong in your region
  • Pollinator magnet: Those unique purple flowers attract native bees and other beneficial insects
  • Drought tolerance: Once established, shieldplant can handle dry conditions like a champ
  • Low maintenance: This isn’t a high-maintenance diva—it thrives with minimal care
  • Unique appearance: The twisted stems and inflated flowers add an unexpected element to garden designs
  • Versatile lifespan: Can function as annual, biennial, or perennial depending on your garden conditions

Best Garden Settings for Shieldplant

Shieldplant isn’t meant for formal, manicured gardens—it’s more of a free spirit! Consider using it in:

  • Native plant gardens
  • Wildflower meadows
  • Rock gardens
  • Naturalized areas
  • Wildlife habitat gardens
  • Low-water landscapes

Growing Conditions and Care

The beauty of native plants like shieldplant is that they’re already adapted to thrive in your local conditions. Here’s what this plant prefers:

Sunlight: Full sun to partial shade—it’s pretty flexible about light conditions

Soil: Well-drained soil is essential. Shieldplant can actually tolerate poor soils better than rich, fertile ones. Think lean and mean rather than rich and pampered.

Water: Drought tolerant once established. Avoid overwatering, which can actually harm the plant.

Climate zones: Hardy in USDA zones 7-10, which aligns perfectly with its native California and Oregon range.

Planting and Care Tips

Growing shieldplant successfully is refreshingly straightforward:

  • Timing: Direct seed in fall or early spring when natural moisture is available
  • Soil prep: Don’t amend your soil too much—this plant prefers lean conditions
  • Watering: Water gently until germination, then reduce frequency as plants establish
  • Maintenance: Once established, step back and let nature take the wheel
  • Patience: Some plants may not bloom until their second year if growing as biennials

The Bottom Line

Shieldplant might not win any beauty contests in the traditional sense, but it offers something far more valuable—authentic regional character and ecological benefits. If you’re looking to create a garden that truly belongs in the western landscape while supporting local pollinators and wildlife, shieldplant deserves serious consideration. Its quirky charm and easy-care nature make it a perfect choice for gardeners who appreciate plants with personality over perfect petals.

Just remember: this is a plant that thrives on benign neglect, so resist the urge to fuss over it. Sometimes the best thing you can do for a native plant is simply give it space to be itself!

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