North America Native Plant

Sonoran Ticktrefoil

Botanical name: Desmodium scopulorum

USDA symbol: DESC3

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Desmodium wigginsii B.G. Schub. (DEWI2)   

Sonoran Ticktrefoil: A Rare Arizona Native Worth Knowing Meet Sonoran ticktrefoil (Desmodium scopulorum), one of Arizona’s lesser-known native treasures. This annual forb might not be the showiest plant in the desert, but it represents something special—a piece of our native botanical heritage that deserves our attention and respect. What Makes ...

Rare plant alert!

Region: Conservation status by state

Status: S3?: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ 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 ⚘

Sonoran Ticktrefoil: A Rare Arizona Native Worth Knowing

Meet Sonoran ticktrefoil (Desmodium scopulorum), one of Arizona’s lesser-known native treasures. This annual forb might not be the showiest plant in the desert, but it represents something special—a piece of our native botanical heritage that deserves our attention and respect.

What Makes Sonoran Ticktrefoil Special?

Sonoran ticktrefoil belongs to the legume family, making it a relative of beans, peas, and other nitrogen-fixing plants. As an annual forb, it completes its entire life cycle in one growing season, sprouting from seed, flowering, producing seeds, and then dying back—all within a single year. This herbaceous plant lacks the woody stems of shrubs and trees, instead producing soft, green growth that emerges fresh each growing season.

Where Does It Call Home?

This Arizona endemic has a very limited range, currently documented only within the state of Arizona. Its restricted distribution makes it a true local specialty—think of it as Arizona’s botanical equivalent to a rare vintage wine that you can only find in one specific vineyard.

A Plant That Needs Our Care

Here’s where things get important: Sonoran ticktrefoil carries a Global Conservation Status of S3?, which indicates there’s some uncertainty about its exact conservation status, but it’s likely uncommon to rare. This means we need to be thoughtful stewards if we’re interested in growing this plant.

If you’re considering adding Sonoran ticktrefoil to your native plant collection, here are the key things to keep in mind:

  • Source responsibly: Only obtain seeds or plants from reputable native plant nurseries that can verify their stock comes from ethical, sustainable sources
  • Never collect from the wild: Given its rarity, wild collection could harm existing populations
  • Consider it a specialty plant: This isn’t your typical garden center find—it’s more like adopting a rare orchid

Why Grow Sonoran Ticktrefoil?

You might wonder why anyone would want to grow a relatively unknown, rare annual. Here’s the thing about native plants—they often provide benefits that aren’t immediately obvious:

  • Authentic local character: Few things say Arizona native garden quite like a plant that grows nowhere else on Earth
  • Ecological connections: As a member of the legume family, it likely supports specialized native insects and contributes to soil health through nitrogen fixation
  • Conservation value: Growing rare natives in gardens can serve as insurance populations and help preserve genetic diversity
  • Educational opportunity: It’s a conversation starter that helps spread awareness about Arizona’s unique flora

Growing Challenges and Considerations

Here’s the honest truth: growing Sonoran ticktrefoil won’t be like planting marigolds. Limited information exists about its specific growing requirements, which means you’d be part gardener, part plant detective. This makes it best suited for:

  • Experienced native plant gardeners who enjoy a challenge
  • People passionate about rare plant conservation
  • Gardeners willing to experiment and potentially fail (it’s part of the rare plant journey!)
  • Those creating specialized Arizona native plant collections

The Bottom Line

Sonoran ticktrefoil represents the fascinating diversity hidden within Arizona’s native plant communities. While it might not be the easiest plant to grow or the most spectacular to look at, it offers something increasingly rare in our world: a genuine connection to a specific place that exists nowhere else.

If you’re drawn to the idea of growing this rare Arizona native, approach it with respect, patience, and realistic expectations. Consider it less of a typical gardening project and more of a conservation effort—one that could help ensure this unique piece of Arizona’s botanical heritage continues to thrive for future generations to discover and appreciate.

Sometimes the most rewarding plants aren’t the ones that bloom the biggest or grow the fastest, but the ones that connect us most deeply to the irreplaceable natural world right in our own backyard.

Sonoran Ticktrefoil

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

Fabales

Family

Fabaceae Lindl. - Pea family

Genus

Desmodium Desv. - ticktrefoil

Species

Desmodium scopulorum S. Watson - Sonoran ticktrefoil

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