North America Native Plant

Roughhairy Maiden Fern

Botanical name: Thelypteris hispidula var. inconstans

USDA symbol: THHII

Life cycle: perennial

Habit: forb

Native status: Native to Puerto Rico âš˜ Native to the U.S. Virgin Islands  

Synonyms: Thelypteris quadrangularis (Fée) Schelpe var. inconstans (C. Chr.) A.R. Sm. (THQUI)   

Roughhairy Maiden Fern: A Tropical Caribbean Native Worth Knowing Meet the roughhairy maiden fern (Thelypteris hispidula var. inconstans), a delightful native fern that calls the sunny Caribbean home. While this particular variety might not be gracing garden centers across the mainland United States, it’s a fascinating example of the unique ...

Roughhairy Maiden Fern: A Tropical Caribbean Native Worth Knowing

Meet the roughhairy maiden fern (Thelypteris hispidula var. inconstans), a delightful native fern that calls the sunny Caribbean home. While this particular variety might not be gracing garden centers across the mainland United States, it’s a fascinating example of the unique plant life that thrives in our tropical territories.

What Exactly Is the Roughhairy Maiden Fern?

Don’t let the roughhairy part of the name scare you off – this perennial fern is actually quite charming! Belonging to the maiden fern family (Thelypteris), this variety showcases the incredible diversity of fern species that have adapted to life in tropical climates. The scientific name might be a mouthful, but you might also see it referred to by its synonym, Thelypteris quadrangularis var. inconstans.

As a true native species, this fern has spent countless years perfecting its survival skills in the unique conditions of Puerto Rico and the U.S. Virgin Islands. It’s part of the rich tapestry of plant life that makes these islands so botanically special.

Where Does It Call Home?

The roughhairy maiden fern is exclusively native to Puerto Rico and the U.S. Virgin Islands, making it a true Caribbean endemic. This limited range makes it particularly special – it’s a plant that has evolved specifically for these island conditions and can’t be found naturally anywhere else in the world.

Is It Beneficial for Gardens?

If you’re lucky enough to live in Puerto Rico or the U.S. Virgin Islands, this native fern could potentially be a wonderful addition to a native plant garden. Native ferns like this one typically offer several benefits:

  • They’re perfectly adapted to local growing conditions
  • They support local ecosystems and wildlife
  • They require less maintenance once established
  • They help preserve regional biodiversity

However, since this particular variety isn’t commonly available in cultivation, you’ll want to work with local native plant specialists if you’re interested in incorporating it into your landscape.

How to Identify This Unique Fern

While specific identification details for this variety are limited, maiden ferns in general tend to share certain characteristics. As a member of the Thelypteris genus, you can expect:

  • Delicate, finely divided fronds
  • A perennial growth habit, returning year after year
  • Adaptation to the warm, humid conditions of the Caribbean
  • The ability to thrive in the specific microclimates of its native islands

A Word About Conservation

Since the roughhairy maiden fern has such a limited native range, it’s particularly important to protect and preserve its natural habitats. If you encounter this fern in the wild during visits to Puerto Rico or the U.S. Virgin Islands, take a moment to appreciate this unique piece of Caribbean biodiversity – but leave it undisturbed for others to enjoy and for the ecosystem to benefit from its presence.

For gardeners outside of its native range, consider exploring native fern species in your own region. Every area has its own special native ferns that can bring that same sense of place and ecological connection to your garden.

Roughhairy 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 hispidula (Decne.) C.F. Reed - roughhairy 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