North America Native Plant

Bristly Bristle Fern

Botanical name: Trichomanes setigerum

USDA symbol: TRSE9

Life cycle: perennial

Habit: forb

Native status: Native to Pacific Basin excluding Hawaii  

Synonyms: Abrodictyum setigerum (Backh. ex T. Moore), ined. (ABSE)  âš˜  Cephalomanes setigerum (Backh. ex T. Moore) I.M. Turner (CESE12)   

Bristly Bristle Fern: A Rare Pacific Treasure for Specialty Gardens Meet the bristly bristle fern (Trichomanes setigerum), one of nature’s most delicate and specialized ferns. This fascinating plant belongs to the filmy fern family, and true to its name, it’s got a distinctly bristly appearance that sets it apart from ...

Bristly Bristle Fern: A Rare Pacific Treasure for Specialty Gardens

Meet the bristly bristle fern (Trichomanes setigerum), one of nature’s most delicate and specialized ferns. This fascinating plant belongs to the filmy fern family, and true to its name, it’s got a distinctly bristly appearance that sets it apart from your typical backyard ferns.

What Makes This Fern Special?

The bristly bristle fern is a perennial forb – essentially a non-woody plant that comes back year after year. What makes it truly unique is its incredibly thin, almost translucent fronds that seem to shimmer in the right light. These delicate leaves are what give filmy ferns their ethereal, almost magical appearance.

You might also see this fern listed under its scientific synonyms Abrodictyum setigerum or Cephalomanes setigerum in some plant databases, but they’re all referring to the same remarkable species.

Where Does It Call Home?

This isn’t your average garden center find. The bristly bristle fern is native to the Pacific Basin, with documented populations in Guam and Palau. It’s perfectly adapted to the humid, tropical conditions of these Pacific islands.

Is This Fern Right for Your Garden?

Here’s where we need to be honest – the bristly bristle fern is definitely not for everyone. This is a specialty plant that requires very specific conditions to thrive:

  • Extremely high humidity (think tropical rainforest levels)
  • Deep, consistent shade
  • Warm temperatures year-round
  • Excellent drainage while maintaining moisture

If you live in USDA hardiness zones 10-12 and can provide these conditions, you might have success with this unique fern. However, for most gardeners, this plant is better admired in its natural habitat or specialized botanical collections.

Alternative Options for Fern Lovers

If you’re drawn to the delicate beauty of filmy ferns but live outside their natural range, consider these alternatives:

  • Native maidenhair ferns for your region
  • Local woodland ferns that thrive in shade
  • Greenhouse or terrarium cultivation for tropical species

Conservation Considerations

Given its limited natural range and specific habitat requirements, the bristly bristle fern represents an important part of Pacific island biodiversity. If you’re lucky enough to encounter this species, it’s worth appreciating it for what it is – a remarkable example of nature’s ability to create beauty in very specific niches.

For most of us, the bristly bristle fern serves as a wonderful reminder that not every plant needs to end up in our gardens to be valuable and worth protecting in its natural environment.

Bristly Bristle Fern

Classification

Group

Fern

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision
Division

Pteridophyta - Ferns

Subdivision
Class

Filicopsida

Subclass
Order

Polypodiales

Family

Hymenophyllaceae Mart. - Filmy Fern family

Genus

Trichomanes L. - bristle fern

Species

Trichomanes setigerum Backh. ex T. Moore - bristly bristle fern

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