North America Native Plant

Boyden Cave Gilia

Botanical name: Gilia yorkii

USDA symbol: GIYO

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Boyden Cave Gilia: A Rare California Native You Shouldn’t Plant Meet Boyden Cave gilia (Gilia yorkii), a tiny annual wildflower that’s so rare, most gardeners will never see one in person. While we usually love to encourage planting native species, this particular California native comes with a big please don’t ...

Rare plant alert!

Region: Conservation status by state

Status: S1: Status is uncertain but is somewhere between the following rankings: 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) ⚘

Boyden Cave Gilia: A Rare California Native You Shouldn’t Plant

Meet Boyden Cave gilia (Gilia yorkii), a tiny annual wildflower that’s so rare, most gardeners will never see one in person. While we usually love to encourage planting native species, this particular California native comes with a big please don’t attached to it.

What Makes This Plant So Special (and Off-Limits)?

Boyden Cave gilia isn’t just uncommon—it’s critically imperiled. With a Global Conservation Status of S1, this little forb is hanging on by a thread in the wild. Scientists estimate there are fewer than 1,000 individual plants remaining, scattered across just five or fewer locations. That’s rarer than finding a four-leaf clover in your backyard!

Where Does It Call Home?

This elusive annual is a true California endemic, meaning you won’t find it growing wild anywhere else on Earth. Its extremely limited range makes it one of the Golden State’s botanical treasures—and one of its most vulnerable.

Why You Shouldn’t Plant It (Even If You Could)

Here’s the thing about critically imperiled plants: they belong in conservation programs, not in our gardens. Even if you somehow stumbled across seeds or plants, growing Boyden Cave gilia would be:

  • Potentially harmful to wild populations if sourced irresponsibly
  • Likely to fail, since we don’t understand its specific growing requirements
  • Taking resources away from conservation efforts where they’re desperately needed

What We Know (And Don’t Know) About Growing Conditions

As an annual forb, Boyden Cave gilia completes its entire life cycle in one growing season. Beyond that basic fact, the specific growing conditions, soil preferences, and care requirements remain largely unknown. This knowledge gap is partly why conservation efforts are so challenging—and why home cultivation isn’t recommended.

Better Alternatives for Your Native Garden

Instead of seeking out this rare gem, consider these more common and garden-friendly California native Gilia species:

  • Bird’s-eye gilia (Gilia tricolor) – stunning blue and white flowers
  • Globe gilia (Gilia capitata) – cheerful blue pom-pom blooms
  • Scarlet gilia (Ipomopsis aggregata) – brilliant red tubular flowers loved by hummingbirds

These alternatives will give you the beauty of native gilias while supporting conservation efforts and providing reliable garden performance.

How You Can Help

While you can’t grow Boyden Cave gilia in your garden, you can still make a difference:

  • Support organizations working on California native plant conservation
  • Choose other native plants for your landscape
  • Spread awareness about rare plant conservation
  • Respect natural areas where rare plants might be growing

Sometimes the best way to love a plant is to leave it alone. Boyden Cave gilia serves as a reminder that our native flora includes species so rare and special that they’re best admired from afar while we work to ensure their survival for future generations.

Boyden Cave Gilia

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Solanales

Family

Polemoniaceae Juss. - Phlox family

Genus

Gilia Ruiz & Pav. - gilia

Species

Gilia yorkii Shevock & Day - Boyden Cave gilia

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