North America Native Plant

San Benito Spineflower

Botanical name: Chorizanthe biloba var. immemora

USDA symbol: CHBII

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

San Benito Spineflower: A Rare California Native Worth Protecting Meet the San Benito spineflower (Chorizanthe biloba var. immemora), one of California’s most elusive native wildflowers. This tiny annual plant might not win any beauty contests, but it holds a special place in the Golden State’s botanical heritage – and it ...

Rare plant alert!

Region: Conservation status by state

Status: S3T1?: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ Subspecies or variety is critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘ 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 ⚘

San Benito Spineflower: A Rare California Native Worth Protecting

Meet the San Benito spineflower (Chorizanthe biloba var. immemora), one of California’s most elusive native wildflowers. This tiny annual plant might not win any beauty contests, but it holds a special place in the Golden State’s botanical heritage – and it desperately needs our protection.

What Makes This Plant Special?

The San Benito spineflower is what botanists call a forb – essentially a non-woody flowering plant that completes its entire life cycle in a single growing season. Don’t expect towering stems or showy blooms; this little guy keeps things modest with small clusters of white to pinkish flowers that bloom briefly before setting seed and calling it a year.

Where Does It Call Home?

This spineflower is a true California endemic, found only in San Benito County. It’s what we call a local celebrity – famous in its tiny corner of the world but virtually unknown everywhere else. The plant is native to the lower 48 states, but its entire world consists of a small patch of specialized habitat in central California.

The Rarity Reality Check

Important Conservation Alert: The San Benito spineflower has a Global Conservation Status of S3T1?, which indicates it’s critically imperiled. This means the species faces an extremely high risk of extinction, making it one of California’s most vulnerable native plants.

What does this mean for gardeners? Simply put, this isn’t a plant you should be growing in your backyard – even if you could get your hands on seeds or plants.

Why You Shouldn’t Grow It (And What to Grow Instead)

Here’s the straight talk: the San Benito spineflower isn’t garden material, and that’s perfectly okay. Here’s why:

  • Its extreme rarity makes collection from wild populations harmful to species survival
  • It requires very specific soil conditions (serpentine soils) that are nearly impossible to replicate
  • As an annual, it lives fast and dies young – not exactly the reliable garden performer most of us want
  • Its specialized habitat needs make cultivation extremely challenging

Better Alternatives for Your Garden

If you’re drawn to California’s spineflower family, consider these more garden-friendly and readily available native alternatives:

  • Turkish rugging (Chorizanthe staticoides) – another spineflower that’s more widely distributed
  • California buckwheat (Eriogonum fasciculatum) – a related species that’s excellent for native gardens
  • Other annual wildflowers native to your specific region of California

How You Can Help

Instead of trying to grow this rare beauty, here’s how you can support the San Benito spineflower:

  • Support organizations working to protect California’s serpentine habitats
  • Choose other native plants for your garden that support local ecosystems
  • Spread awareness about the importance of protecting rare native species
  • If you’re in the area, respect habitat boundaries and never collect wild plants

The Bottom Line

The San Benito spineflower reminds us that not every native plant belongs in our gardens – and that’s a beautiful thing. Some species are meant to thrive in their wild homes, protected and admired from a respectful distance. By understanding and respecting these boundaries, we become better stewards of California’s incredible botanical diversity.

Remember: the best way to appreciate rare plants like the San Benito spineflower is to protect their natural habitats and choose abundant, garden-appropriate natives for our own landscapes. Your local native plant society can help you find the perfect California natives that will thrive in your garden while supporting local wildlife.

San Benito Spineflower

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Caryophyllidae

Order

Polygonales

Family

Polygonaceae Juss. - Buckwheat family

Genus

Chorizanthe R. Br. ex Benth. - spineflower

Species

Chorizanthe biloba Goodman - twolobe spineflower

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