North America Native Plant

Island Mountain Mahogany

Botanical name: Cercocarpus montanus var. blancheae

USDA symbol: CEMOB

Life cycle: perennial

Habit: shrub

Native status: Native to the lower 48 states  

Synonyms: Cercocarpus alnifolius Rydb. (CEAL8)  âš˜  Cercocarpus betuloides Nutt. var. blancheae (C.K. Schneid.) Little (CEBEB)  âš˜  Cercocarpus montanus Raf. ssp. blancheae (C.K. Schneid.) Thorne (CEMOB2)   

Island Mountain Mahogany: A Rare California Native Worth Knowing Meet the island mountain mahogany (Cercocarpus montanus var. blancheae), a fascinating native shrub that calls California home. While this particular variety might not be a household name among gardeners, it represents an important piece of California’s native plant heritage that deserves ...

Rare plant alert!

Region: Conservation status by state

Status: S5T3: Status is uncertain but is somewhere between the following rankings: 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. ⚘ Secure: At very low or no risk of extinction in the jurisdiction due to a very extensive range, abundant populations or occurrences, with little to no concern from declines or threats. ⚘

Island Mountain Mahogany: A Rare California Native Worth Knowing

Meet the island mountain mahogany (Cercocarpus montanus var. blancheae), a fascinating native shrub that calls California home. While this particular variety might not be a household name among gardeners, it represents an important piece of California’s native plant heritage that deserves our attention and respect.

What Makes This Plant Special

The island mountain mahogany is a perennial shrub that typically grows as a multi-stemmed woody plant, usually staying under 13-16 feet in height. Like other shrubs in its family, it develops several stems from near the ground, creating a naturally bushy appearance that can add structure and native character to the right landscape.

This plant goes by several scientific names in botanical literature, including Cercocarpus alnifolius, Cercocarpus betuloides var. blancheae, and Cercocarpus montanus ssp. blancheae – a testament to the ongoing work botanists do to understand plant relationships and classifications.

Where You’ll Find It

This native beauty is found exclusively in California, making it a true Golden State endemic. As a plant that’s native to the lower 48 states, it has deep roots in local ecosystems and has evolved alongside California’s unique climate and wildlife.

A Word About Rarity

Here’s something important to know: island mountain mahogany has a Global Conservation Status of S5T3, which indicates it has some conservation concerns. This means that while you might be intrigued by this native plant, it’s crucial to source any plants responsibly from reputable native plant nurseries that propagate their stock rather than wild-collect it. Never collect plants or seeds from wild populations.

Should You Grow Island Mountain Mahogany?

The honest answer is that specific growing information for this particular variety is quite limited in available resources. While we know it’s a California native shrub with the typical characteristics of mountain mahogany plants, detailed cultivation requirements, hardiness zones, and specific care instructions for var. blancheae aren’t well-documented in common horticultural sources.

If you’re drawn to this plant, consider these factors:

  • You’re committed to supporting California native plants
  • You can source plants from reputable native plant nurseries
  • You’re willing to work with limited specific growing guidance
  • You have experience with other mountain mahogany species

Alternative Native Options

Given the limited cultivation information and conservation status of this particular variety, you might consider other California native shrubs that are better documented and more readily available. Plants in the same genus, like other Cercocarpus species, or related California native shrubs might give you similar aesthetic and ecological benefits with more reliable growing guidance.

The Bottom Line

Island mountain mahogany represents the kind of specialized native plant that makes California’s flora so unique and valuable. While it might not be the easiest choice for every gardener, it serves as a reminder of the incredible diversity hiding in our native landscapes. Whether you choose to grow this particular variety or not, supporting native plant conservation and responsible gardening practices helps ensure that rarities like this continue to thrive in their natural habitats.

If you do decide to seek out this plant, connect with your local native plant society or specialized native plant nurseries – they’re your best bet for accurate, location-specific growing advice and responsibly sourced plants.

Island Mountain Mahogany

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

Rosales

Family

Rosaceae Juss. - Rose family

Genus

Cercocarpus Kunth - mountain mahogany

Species

Cercocarpus montanus Raf. - alderleaf mountain mahogany

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