North America Native Plant

California Buckthorn

Botanical name: Frangula californica ursina

USDA symbol: FRCAU

Life cycle: perennial

Habit: shrub

Native status: Native to the lower 48 states  

Synonyms: Rhamnus californica Eschsch. ssp. ursina (Greene) C.B. Wolf (RHCAU2)  âš˜  Rhamnus californica Eschsch. var. ursina (Greene) McMinn (RHCAU3)  âš˜  Rhamnus tomentella Benth. ssp. ursina (Greene) J.O. Sawyer (RHTOU)   

California Buckthorn: A Native Shrub for Southwestern Gardens Meet Frangula californica ursina, commonly known as California buckthorn – a native shrub that might just be the unsung hero your garden has been waiting for. While this particular subspecies doesn’t get as much spotlight as some of its flashier native cousins, ...

California Buckthorn: A Native Shrub for Southwestern Gardens

Meet Frangula californica ursina, commonly known as California buckthorn – a native shrub that might just be the unsung hero your garden has been waiting for. While this particular subspecies doesn’t get as much spotlight as some of its flashier native cousins, it brings its own unique charm to southwestern landscapes.

Where Does California Buckthorn Call Home?

This resilient shrub is a true native of the American Southwest, naturally growing across Arizona, California, Nevada, and New Mexico. As a perennial woody plant native to the lower 48 states, it’s perfectly adapted to the challenging conditions these regions can dish out.

What to Expect: Size and Growth

California buckthorn is a multi-stemmed shrub that typically stays under 13-16 feet tall, though it can occasionally stretch taller or grow with a single stem depending on its environment. Like many native shrubs, it develops several stems from or near ground level, creating a naturally full appearance that works beautifully in landscape designs.

The Challenge: Limited Information

Here’s where things get a bit tricky – while we know this subspecies exists and where it grows, detailed information about Frangula californica ursina specifically is surprisingly scarce. This means that much of what we know comes from observing the broader California buckthorn family, but the exact growing requirements, appearance details, and care needs of this particular subspecies remain somewhat mysterious.

Should You Plant It?

The short answer? Probably not, and here’s why:

  • Limited availability: Since this subspecies isn’t well-documented, finding reliable plant sources could be challenging
  • Unknown growing requirements: Without specific care information, you’d be gardening by guesswork
  • Uncertain identification: You might end up with a different variety entirely

Better Native Alternatives

Instead of hunting for this elusive subspecies, consider these well-documented native alternatives that offer similar benefits:

  • Standard Frangula californica (California buckthorn) – better documented and more readily available
  • Other native buckthorn species suited to your specific region
  • Native shrubs with similar growth habits and ecological benefits

If You’re Determined to Try

Should you somehow locate this subspecies, treat it like you would other California buckthorn varieties – provide well-draining soil and expect it to be drought-tolerant once established. However, proceed with caution and consider working with local native plant experts who might have more specific knowledge about regional subspecies.

The Bottom Line

While Frangula californica ursina is undoubtedly a fascinating native plant, the lack of detailed information makes it a risky choice for most gardeners. Your time and energy might be better invested in its better-known relatives or other well-documented native shrubs that can provide similar ecological benefits with much more predictable results.

Sometimes in native gardening, the most responsible choice is admitting when we don’t know enough – and this subspecies falls squarely into that category.

California Buckthorn

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

Rhamnales

Family

Rhamnaceae Juss. - Buckthorn family

Genus

Frangula Mill. - buckthorn

Species

Frangula californica (Eschsch.) A. Gray - California buckthorn

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