North America Native Plant

California Goldenbanner

Botanical name: Thermopsis californica var. semota

USDA symbol: THCAS2

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Thermopsis macrophylla Hook. & Arn. var. semota Jeps. (THMAS)  âš˜  Thermopsis macrophylla Hook. & Arn. ssp. semota (Jeps.) R.M. Beauch. (THMAS2)   

California Goldenbanner: A Rare Native Gem Worth Protecting Meet California goldenbanner (Thermopsis californica var. semota), a perennial wildflower that’s as rare as it is beautiful. This native California plant belongs to the pea family and represents one of nature’s more elusive treasures in the Golden State’s botanical landscape. What Makes ...

Rare plant alert!

Region: Conservation status by state

Status: S3T2: Status is uncertain but is somewhere between the following rankings: Subspecies or variety is imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘ 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 Goldenbanner: A Rare Native Gem Worth Protecting

Meet California goldenbanner (Thermopsis californica var. semota), a perennial wildflower that’s as rare as it is beautiful. This native California plant belongs to the pea family and represents one of nature’s more elusive treasures in the Golden State’s botanical landscape.

What Makes California Goldenbanner Special

California goldenbanner is a herbaceous perennial forb, meaning it’s a non-woody plant that dies back to the ground each winter and returns from its roots each spring. As a member of the legume family, it shares characteristics with other pea-family plants, likely producing clusters of bright yellow, pea-like flowers that give it the goldenbanner name.

Where You’ll Find This Rare Beauty

This plant is endemic to California, meaning it grows nowhere else on Earth naturally. Its limited distribution makes it a true California native that has evolved specifically for the unique conditions found within the state’s diverse ecosystems.

Conservation Status: Handle With Care

Here’s something important every gardener should know: California goldenbanner has a Global Conservation Status of S3T2, indicating it’s quite rare. This means if you’re lucky enough to encounter this plant or want to grow it, you’ll need to be extra thoughtful about sourcing.

If you want to grow California goldenbanner:

  • Only purchase from reputable native plant nurseries that can verify responsible sourcing
  • Never collect seeds or plants from wild populations
  • Consider it a conservation effort as much as a gardening project
  • Check with local native plant societies for guidance on availability

Growing California Goldenbanner

Unfortunately, detailed growing information specific to this variety is limited due to its rarity. However, as a California native perennial forb, it likely prefers:

  • Well-draining soil (most California natives dislike soggy feet)
  • Minimal summer water once established
  • Full sun to partial shade conditions
  • Protection from strong winds in exposed locations

Since this plant belongs to the legume family, it may have the ability to fix nitrogen in the soil through root bacteria, potentially benefiting neighboring plants.

Why Consider This Rare Native?

Growing California goldenbanner isn’t just about adding another plant to your garden—it’s about participating in conservation. When you choose rare natives like this one, you’re:

  • Supporting biodiversity in your local ecosystem
  • Creating habitat for native pollinators and wildlife
  • Preserving California’s unique botanical heritage
  • Reducing the need for water and fertilizers compared to non-native alternatives

The Bottom Line

California goldenbanner is a plant for the dedicated native gardener who values conservation as much as beauty. While it may not be the easiest plant to find or grow, its rarity makes it a special addition to native plant collections. If you’re interested in growing this species, connect with local native plant societies, botanical gardens, or specialized native nurseries who can guide you toward responsibly sourced plants.

Remember, every rare native plant we successfully cultivate in our gardens is a small victory for conservation—and California goldenbanner definitely qualifies as a plant worth protecting for future generations.

California Goldenbanner

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Rosidae

Order

Fabales

Family

Fabaceae Lindl. - Pea family

Genus

Thermopsis R. Br. - goldenbanner

Species

Thermopsis californica S. Watson - California goldenbanner

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