North America Native Plant

Sonoran Maiden Fern

Botanical name: Thelypteris puberula var. sonorensis

USDA symbol: THPUS

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Discovering the Sonoran Maiden Fern: A Rare Southwestern Native If you’re a fern enthusiast with a passion for rare native plants, you might be intrigued by the Sonoran maiden fern (Thelypteris puberula var. sonorensis). This perennial fern represents a unique variety of the maiden fern family, specifically adapted to the ...

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. ⚘

Discovering the Sonoran Maiden Fern: A Rare Southwestern Native

If you’re a fern enthusiast with a passion for rare native plants, you might be intrigued by the Sonoran maiden fern (Thelypteris puberula var. sonorensis). This perennial fern represents a unique variety of the maiden fern family, specifically adapted to the challenging conditions of the American Southwest.

Where Does It Call Home?

The Sonoran maiden fern is native to the lower 48 states, with its range specifically including Arizona and California. As its common name suggests, this fern has evolved to thrive in the Sonoran Desert region and surrounding areas, making it quite different from its moisture-loving fern cousins.

What Makes This Fern Special?

Unlike the towering tree ferns or the delicate maidenhair varieties you might know, the Sonoran maiden fern is classified as a forb – essentially a non-woody perennial plant. This means it lacks the significant woody tissue you’d find in shrubs or trees, instead maintaining a more herbaceous growth pattern that’s perfectly adapted to its arid environment.

A Word of Caution: Rarity Matters

Here’s something important to know before you start planning your fern garden: the Sonoran maiden fern has a Global Conservation Status of S5T3, which indicates it may face some conservation challenges. If you’re considering adding this unique native to your landscape, it’s crucial to source it responsibly from reputable native plant nurseries that propagate their stock rather than wild-collect it.

Is This Fern Right for Your Garden?

The Sonoran maiden fern could be an excellent choice if you’re:

  • Creating a native plant garden focused on southwestern species
  • Looking for unique ferns adapted to drier conditions
  • Interested in supporting local biodiversity and conservation efforts
  • Developing a specialized collection of rare native plants

However, this might not be the fern for you if you’re a beginning gardener or looking for readily available, low-maintenance options. Its rarity means it may be challenging to source and could require more specialized care knowledge.

Growing Tips for Success

While specific growing information for this variety is limited, most southwestern native ferns appreciate:

  • Well-draining soil that doesn’t stay soggy
  • Protection from intense afternoon sun
  • Consistent but moderate watering
  • Good air circulation

Since this is a rare variety, consider connecting with local native plant societies or botanical gardens in Arizona and California for region-specific growing advice and potential sources.

The Bottom Line

The Sonoran maiden fern represents a fascinating example of how plants adapt to challenging environments. While its rarity means it’s not a casual garden choice, dedicated native plant enthusiasts who can source it responsibly may find it a rewarding addition to specialized southwestern native gardens. Just remember – with rare plants comes great responsibility to help preserve them for future generations!

Sonoran Maiden Fern

Classification

Group

Fern

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision
Division

Pteridophyta - Ferns

Subdivision
Class

Filicopsida

Subclass
Order

Polypodiales

Family

Thelypteridaceae Ching ex Pic. Serm. - Marsh Fern family

Genus

Thelypteris Schmidel - maiden fern

Species

Thelypteris puberula (Baker) Morton - showy maiden fern

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