North America Native Plant

Modoc Buckthorn

Botanical name: Frangula rubra modocensis

USDA symbol: FRRUM

Life cycle: perennial

Habit: shrub

Native status: Native to the lower 48 states  

Synonyms: Rhamnus rubra Greene ssp. modocensis C.B. Wolf (RHRUM)   

Modoc Buckthorn: A Rare California Native Worth Knowing About If you’re passionate about native plants and love discovering lesser-known species, you might have stumbled upon Modoc buckthorn (Frangula rubra modocensis). This intriguing California native is one of those plants that doesn’t make it into every field guide, but deserves a ...

Rare plant alert!

Region: Conservation status by state

Status: S4T3?: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ Subspecies or variety is 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. ⚘ Apparently Secure: Uncommon but not rare, and usually widespread. Possibly cause for longterm concern. Typically more than 100 occurrences in the state or more than 10,000 individuals ⚘

Modoc Buckthorn: A Rare California Native Worth Knowing About

If you’re passionate about native plants and love discovering lesser-known species, you might have stumbled upon Modoc buckthorn (Frangula rubra modocensis). This intriguing California native is one of those plants that doesn’t make it into every field guide, but deserves a spot in the conversation about regional biodiversity and specialized native gardening.

What is Modoc Buckthorn?

Modoc buckthorn is a perennial shrub that’s part of the buckthorn family. Like many of its relatives, it’s a multi-stemmed woody plant that typically stays under 13-16 feet tall, making it a manageable size for most garden situations. You might also see it listed under its synonym, Rhamnus rubra Greene ssp. modocensis, if you’re diving deep into botanical literature.

Where Does It Grow?

This native beauty calls California home, though its exact range within the state appears to be quite limited. As a native to the lower 48 states, it has evolved specifically to thrive in California’s unique climate conditions.

A Word of Caution: Rarity Matters

Here’s where things get interesting—and important. Modoc buckthorn has a Global Conservation Status of S4T3?, which essentially means its conservation status is undefined or uncertain. This is botanist-speak for we’re not entirely sure how rare or common this plant is, but it warrants attention.

What does this mean for you as a gardener? If you’re considering adding this plant to your landscape, it’s crucial to source it responsibly. This means:

  • Never collect from wild populations
  • Only purchase from reputable native plant nurseries that propagate their own stock
  • Consider supporting conservation efforts by growing responsibly sourced plants
  • Connect with local native plant societies for guidance

Should You Grow Modoc Buckthorn?

The honest answer is: it depends on your goals and access to properly sourced plants. If you’re passionate about supporting California’s native biodiversity and can find responsibly propagated specimens, this could be a meaningful addition to a specialized native plant collection.

However, if you’re just starting your native gardening journey, you might want to begin with more readily available California natives that provide similar ecological benefits. There are plenty of other native shrubs that offer reliable beauty and wildlife support while being easier to source ethically.

Growing Conditions and Care

Unfortunately, specific growing requirements for Modoc buckthorn aren’t well documented in readily available sources. This is often the case with rare or regionally specific plants. If you do acquire this plant, your best bet is to:

  • Consult with the nursery where you purchased it about specific care requirements
  • Connect with local native plant experts or extension services
  • Observe how it responds in your specific microclimate
  • Provide conditions similar to other California native shrubs as a starting point

The Bottom Line

Modoc buckthorn represents the fascinating diversity of California’s native flora, but it’s not a plant to choose lightly. Its uncertain conservation status means that growing it comes with responsibility. If you’re drawn to rare natives and committed to ethical sourcing, it could be a special addition to your garden. Otherwise, there are many other California natives that can provide beauty, wildlife habitat, and ecological benefits without the conservation concerns.

Remember, the best native garden is one that supports local ecosystems while being sustainable and responsible. Sometimes that means choosing the rare gems, and sometimes it means celebrating the more common natives that are just as valuable to our local wildlife.

Modoc 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 rubra (Greene) V. Grub. - red buckthorn

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