North America Non-native Plant

Diellia Pumila

Botanical name: Diellia pumila

USDA symbol: DIPU8

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

Diellia pumila: Hawaii’s Tiny Treasure Fern Meet one of Hawaii’s most delicate native treasures – Diellia pumila, a petite fern that packs a big punch in the charm department. This little beauty might not have a catchy common name, but what it lacks in marketing appeal, it more than makes ...

Diellia pumila: Hawaii’s Tiny Treasure Fern

Meet one of Hawaii’s most delicate native treasures – Diellia pumila, a petite fern that packs a big punch in the charm department. This little beauty might not have a catchy common name, but what it lacks in marketing appeal, it more than makes up for with its intricate, lacy fronds and fascinating story.

What Makes This Fern Special?

Diellia pumila is what botanists call an endemic species, meaning it’s found nowhere else on Earth except in its native Hawaiian islands. This tiny fern calls Oahu and Molokai home, where it has evolved to thrive in very specific conditions over thousands of years. Think of it as Hawaii’s own botanical celebrity – rare, beautiful, and worth getting excited about.

Identifying Diellia pumila

So how do you spot this Hawaiian gem? Here’s what to look for:

  • Small, compact size that stays petite
  • Finely divided, delicate fronds with an intricate, lacy appearance
  • Elegant texture that adds fine detail to any planting
  • Typically found in shaded, protected areas

Is It Beneficial for Your Garden?

If you’re lucky enough to live in USDA hardiness zones 10-12 and want to create an authentic Hawaiian landscape, Diellia pumila could be a wonderful addition. Here’s what it brings to the table:

  • Adds delicate texture and visual interest to shade gardens
  • Perfect for rock gardens where its small size won’t get overwhelmed
  • Excellent container plant for patios and lanais
  • Supports native Hawaiian ecosystem when grown from responsibly sourced material

Growing Conditions and Care

This little fern has some specific preferences, but don’t let that scare you off:

  • Light: Partial to full shade – think dappled sunlight, not blazing afternoon sun
  • Soil: Well-draining but consistently moist soil with organic matter
  • Water: Regular watering, but avoid soggy conditions
  • Climate: Tropical to subtropical only (zones 10-12)
  • Protection: Shelter from strong winds and direct sun

A Word About Conservation

Here’s where things get serious for a moment. As a Hawaiian endemic, Diellia pumila may be rare in the wild, and its populations could be vulnerable. If you’re interested in growing this special fern, please make sure you source it responsibly from reputable nurseries that propagate rather than wild-collect their plants. Never harvest from wild populations – let’s keep these botanical treasures thriving in their natural habitat for future generations to enjoy.

Perfect For the Right Gardener

Diellia pumila isn’t for everyone, and that’s okay! This fern is ideal for gardeners who:

  • Live in tropical or subtropical climates
  • Appreciate subtle, delicate beauty over flashy flowers
  • Want to support native Hawaiian plant conservation
  • Enjoy the challenge of growing something truly special
  • Have shaded garden spaces that need fine-textured interest

While this little fern won’t attract butterflies like flowering plants do, it offers something equally valuable – a connection to Hawaii’s unique natural heritage and the quiet satisfaction of nurturing something truly rare and beautiful.

Diellia Pumila

Classification

Group

Fern

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision
Division

Pteridophyta - Ferns

Subdivision
Class

Filicopsida

Subclass
Order

Polypodiales

Family

Aspleniaceae Newman - Spleenwort family

Genus

Diellia Brack. - island spleenwort

Species

Diellia pumila Brack. [excluded]

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