North America Native Plant

Mule Mountain Brickellbush

Botanical name: Asanthus squamulosus

USDA symbol: ASSQ

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Synonyms: Brickellia squamulosa A. Gray (BRSQ)   

Mule Mountain Brickellbush: A Rare Southwest Native Worth Knowing If you’re looking to add some authentic Southwest character to your native garden, you might want to get acquainted with Mule Mountain brickellbush (Asanthus squamulosus). This little-known perennial shrub is a true regional treasure, though it comes with some important considerations ...

Rare plant alert!

Region: Conservation status by state

Status: S3S4: Status is uncertain but is somewhere between the following rankings: 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 ⚘

Mule Mountain Brickellbush: A Rare Southwest Native Worth Knowing

If you’re looking to add some authentic Southwest character to your native garden, you might want to get acquainted with Mule Mountain brickellbush (Asanthus squamulosus). This little-known perennial shrub is a true regional treasure, though it comes with some important considerations for the conscientious gardener.

What Makes Mule Mountain Brickellbush Special?

Mule Mountain brickellbush is a compact, low-growing perennial shrub that stays delightfully manageable in the landscape. This petite powerhouse typically maxes out at just 1.5 feet tall, though it can occasionally reach up to 3 feet at maturity. Its modest stature makes it perfect for gardeners who want native authenticity without overwhelming their space.

You might also encounter this plant listed under its botanical synonym, Brickellia squamulosa, which can be helpful when searching for seeds or plants from specialty native plant nurseries.

Where Does It Call Home?

This charming shrub is a true child of the American Southwest, calling Arizona and New Mexico home. It’s perfectly adapted to the unique conditions of this region, making it an excellent choice for gardeners wanting to celebrate their local plant heritage.

A Word of Caution: Rarity Matters

Before you start planning where to plant your Mule Mountain brickellbush, there’s something important to know. This species has a Global Conservation Status of S3S4, indicating it’s considered somewhat rare in its native range. This doesn’t mean you can’t grow it, but it does mean you should be extra thoughtful about how you source it.

If you decide to add this special plant to your garden, make sure you’re getting it from a reputable native plant nursery that sources their plants responsibly. Never collect plants from the wild – this can harm already vulnerable populations.

Is This Plant Right for Your Garden?

Mule Mountain brickellbush could be a fantastic addition to your landscape if you’re gardening in Arizona or New Mexico and want to support local plant diversity. Its compact size makes it versatile for various garden situations, from rock gardens to native plant borders.

However, the limited information available about this species means you’ll be somewhat pioneering in your growing efforts. While this can be exciting for adventurous gardeners, it might be challenging for beginners who prefer plants with well-established care guidelines.

Growing Conditions and Care

As a native of the Southwest, Mule Mountain brickellbush likely prefers conditions similar to other plants from this region. While specific growing requirements aren’t well-documented, you can probably expect it to appreciate:

  • Well-draining soil (essential for most Southwest natives)
  • Full sun to partial shade
  • Low to moderate water once established
  • Protection from excessive moisture

Since detailed care information is limited, consider reaching out to local native plant societies or extension offices in Arizona and New Mexico for region-specific growing advice.

The Bottom Line

Mule Mountain brickellbush represents an opportunity to grow something truly special and support regional biodiversity. Its compact size and perennial nature make it potentially valuable for Southwest native gardens. However, its rarity status means this isn’t a plant to choose lightly – make sure you’re committed to responsible sourcing and patient cultivation.

If you’re new to native gardening or looking for easier alternatives, consider starting with more common Southwest natives like desert marigold, brittlebush, or penstemon species. These will give you experience with regional growing conditions while you decide if you’re ready to take on the rewarding challenge of growing something as special as Mule Mountain brickellbush.

Mule Mountain Brickellbush

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

Asterales

Family

Asteraceae Bercht. & J. Presl - Aster family

Genus

Asanthus R.M. King & H. Rob. - brickellbush

Species

Asanthus squamulosus (A. Gray) R.M. King & H. Rob. - Mule Mountain brickellbush

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