North America Native Plant

Smooth Dwarf Polypody

Botanical name: Grammitis mollissima

USDA symbol: GRMO

Life cycle: perennial

Habit: forb

Native status: Native to Puerto Rico  

Synonyms: Polypodium mollissimum Fée (POMO11)   

Smooth Dwarf Polypody: A Delicate Puerto Rican Fern for Tropical Gardens Meet the smooth dwarf polypody (Grammitis mollissima), a charming little fern that’s as delicate as its name suggests. This petite Puerto Rican native might be small in stature, but it packs a big punch when it comes to adding ...

Smooth Dwarf Polypody: A Delicate Puerto Rican Fern for Tropical Gardens

Meet the smooth dwarf polypody (Grammitis mollissima), a charming little fern that’s as delicate as its name suggests. This petite Puerto Rican native might be small in stature, but it packs a big punch when it comes to adding tropical elegance to the right garden setting.

What Makes This Fern Special

The smooth dwarf polypody is a perennial epiphytic fern that’s perfectly adapted to life in Puerto Rico’s lush montane forests. Unlike the ground-dwelling ferns you might be familiar with, this little beauty naturally grows on trees and rocks, making it a fascinating addition to any tropical plant collection.

You might also encounter this fern under its scientific synonym, Polypodium mollissimum, but regardless of what you call it, its soft, delicate fronds are unmistakable once you know what to look for.

Where You’ll Find It Growing Wild

This fern is endemic to Puerto Rico, where it thrives in the island’s humid mountain forests. It’s perfectly adapted to the tropical climate and high humidity levels found in these elevated regions.

Why Consider Growing Smooth Dwarf Polypody

If you’re lucky enough to live in USDA hardiness zones 10-12, this little fern can be a delightful addition to your garden for several reasons:

  • Its compact size makes it perfect for small spaces, terrariums, or container gardens
  • The soft, delicate texture adds visual interest and contrast to broader-leafed plants
  • As an epiphyte, it can create stunning displays when mounted on tree bark or decorative surfaces
  • It’s a conversation starter – not many people have seen a true dwarf polypody!

Creating the Right Environment

Successfully growing smooth dwarf polypody is all about mimicking its natural habitat. Think tropical cloud forest and you’re on the right track:

  • Light: Bright, filtered light – never direct sunlight
  • Humidity: High humidity levels (60-80%) are essential
  • Air circulation: Good airflow prevents fungal issues
  • Substrate: Well-draining, organic material like bark or moss
  • Temperature: Consistent warm temperatures between 65-80°F

Perfect Garden Settings

This fern shines in specific garden situations:

  • Tropical shade gardens with high humidity
  • Enclosed patios or courtyards in tropical climates
  • Greenhouse collections
  • Large terrariums or vivariums
  • Mounted displays on tree trunks or decorative bark

Care Tips for Success

Keep your smooth dwarf polypody happy with these simple care guidelines:

  • Water regularly to maintain consistent moisture, but avoid waterlogging
  • Mist frequently to maintain humidity levels
  • Use distilled or rainwater when possible
  • Provide gentle air movement with a small fan if growing indoors
  • Remove any dead fronds to maintain plant health

A Note About Sourcing

Since this fern is native only to Puerto Rico, make sure any plants you acquire are responsibly sourced from reputable nurseries rather than wild-collected specimens. This helps protect wild populations while still allowing you to enjoy this unique species.

The smooth dwarf polypody might not be the easiest fern to grow, but for gardeners who love a challenge and have the right tropical conditions, it’s a rewarding addition that brings a piece of Puerto Rico’s mountain forests right to your garden.

Smooth Dwarf Polypody

Classification

Group

Fern

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision
Division

Pteridophyta - Ferns

Subdivision
Class

Filicopsida

Subclass
Order

Polypodiales

Family

Grammitidaceae Newman - Kihi Fern family

Genus

Grammitis Sw. - dwarf polypody

Species

Grammitis mollissima (Fée) Proctor - smooth dwarf polypody

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