North America Non-native Plant

Thelypteris Guamensis

Botanical name: Thelypteris guamensis

USDA symbol: THGU2

Life cycle: perennial

Habit: forb

Native status: Not native but doesn't reproduce and persist in the wild

Thelypteris guamensis: The Mysterious Fern That’s Hard to Find If you’ve stumbled across the name Thelypteris guamensis while browsing plant lists or botanical databases, you’re not alone in wondering what exactly is this plant? This perennial fern species is something of an enigma in the gardening world, with very little ...

Thelypteris guamensis: The Mysterious Fern That’s Hard to Find

If you’ve stumbled across the name Thelypteris guamensis while browsing plant lists or botanical databases, you’re not alone in wondering what exactly is this plant? This perennial fern species is something of an enigma in the gardening world, with very little readily available information about its characteristics, appearance, or cultivation needs.

What We Know About This Elusive Fern

Thelypteris guamensis belongs to the fern family, making it a fascinating non-flowering plant that reproduces through spores rather than seeds. As a perennial, it would theoretically return year after year once established. The species name guamensis suggests a connection to Guam or the broader Pacific region, though specific distribution information is currently unclear.

Interestingly, this fern is classified as having a facultative wetland status in Hawaii, meaning it can grow in both wet and dry conditions – a pretty handy trait for a plant!

The Challenge for Gardeners

Here’s where things get tricky for anyone interested in growing this fern: reliable information about Thelypteris guamensis is extremely limited. We don’t have clear details about:

  • Its physical appearance and size
  • Specific growing requirements
  • Where it can be obtained
  • Its conservation status
  • Whether it’s suitable for home cultivation

What This Means for Your Garden

Given the lack of available information and unclear availability, Thelypteris guamensis isn’t a practical choice for most gardeners. If you’re drawn to the idea of growing Pacific ferns or adding unique fern species to your collection, you might want to consider better-documented alternatives that are readily available and have established cultivation guidelines.

Alternative Fern Options

If you’re interested in ferns for your garden, consider these well-known options instead:

  • Native ferns specific to your region
  • Other Thelypteris species that are better documented
  • Local nursery recommendations for suitable fern varieties

The Bottom Line

While Thelypteris guamensis may intrigue plant enthusiasts with its mysterious nature, the lack of cultivation information makes it an impractical choice for home gardeners. Sometimes the most responsible approach is to focus on well-documented native plants that we know will thrive in our gardens and support local ecosystems.

If you’re specifically interested in this species for research purposes, consider reaching out to botanical institutions or specialized fern societies who might have more detailed information about this elusive plant.

Wetland Status

The rule of seasoned gardeners and landscapers is to choose the "right plant for the right place" matching plants to their ideal growing conditions, so they'll thrive with less work and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection is. While tags list watering requirements, there's more to the story.

Knowing a plant's wetland status can simplify the process by revealing the interaction between plants, water, and soil. Surprisingly, many popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. Also, it helps you make smarter gardening choices and grow healthy plants with less care and feeding, saving you time, frustration, and money while producing an attractive garden with greater ecological benefits.

Regions
Status
Moisture Conditions

Hawaii

FAC

Facultative - Plants with this status can occur in wetlands and non-wetlands

Thelypteris Guamensis

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 guamensis (Holttum) Fosberg & Sachet

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