North America Native Plant

Necklace Island Spleenwort

Botanical name: Diellia leucostegioides

USDA symbol: DILE9

Life cycle: perennial

Habit: forb

Native status: Native to Hawaii  

Synonyms: Asplenium leucostegioides Baker (ASLE22)   

The Elusive Necklace Island Spleenwort: A Vanishing Treasure of Hawaii Meet the necklace island spleenwort, one of Hawaii’s most enigmatic and heartbreakingly rare native ferns. With the botanical name Diellia leucostegioides, this delicate island endemic tells a story of both natural wonder and conservation concern that every native plant enthusiast ...

Rare plant alert!

Region: Conservation status by state

Status: SH: Status is uncertain but is somewhere between the following rankings: Possibly Extinct: Known only from historical occurrences. Still some hope of rediscovery ⚘

The Elusive Necklace Island Spleenwort: A Vanishing Treasure of Hawaii

Meet the necklace island spleenwort, one of Hawaii’s most enigmatic and heartbreakingly rare native ferns. With the botanical name Diellia leucostegioides, this delicate island endemic tells a story of both natural wonder and conservation concern that every native plant enthusiast should know about.

What Is the Necklace Island Spleenwort?

Despite being classified in some databases as a forb, the necklace island spleenwort is actually a true fern belonging to the Diellia genus. This perennial fern was once part of Hawaii’s rich understory ecosystem, contributing to the incredible diversity that makes the Hawaiian Islands a botanical paradise. The species also goes by the synonym Asplenium leucostegioides in older botanical literature.

Where Does It Come From?

The necklace island spleenwort is endemic to Hawaii, meaning it exists nowhere else on Earth. This native species evolved in isolation over millions of years, developing unique characteristics that helped it thrive in Hawaii’s specific environmental conditions.

The Conservation Crisis

Here’s where the story takes a sobering turn. The necklace island spleenwort has a Global Conservation Status of SH, which stands for Possibly Extirpated. In plain English, this means:

  • The fern is known only from historical records
  • No confirmed populations have been found in recent years
  • There’s still some hope it might be rediscovered in remote locations
  • It may already be extinct

This classification puts the necklace island spleenwort among Hawaii’s most critically endangered plants, highlighting the ongoing biodiversity crisis facing the Hawaiian Islands.

Should You Try to Grow It?

The short answer is absolutely not – and here’s why. Given its possibly extirpated status, any remaining plants (if they exist) are incredibly precious for conservation efforts. Home gardeners should never attempt to collect or grow this species because:

  • It may no longer exist in the wild
  • Any surviving plants need to be preserved for scientific study and potential restoration efforts
  • Growing conditions and propagation methods are largely unknown
  • It would likely require specialized greenhouse conditions that most home gardeners cannot provide

What You Can Do Instead

While you can’t grow the necklace island spleenwort, you can still honor Hawaii’s fern heritage by choosing other native Hawaiian ferns for your garden. Consider these alternatives:

  • Hawaiian tree fern (Cibotium chamissoi)
  • Kupukupu fern (Nephrolepis cordifolia)
  • Palapalai fern (Microlepia strigosa)

These species are more readily available from reputable native plant nurseries and can help you create a beautiful Hawaiian native garden while supporting conservation efforts.

The Bigger Picture

The story of the necklace island spleenwort serves as a powerful reminder of what we stand to lose when native ecosystems are disrupted. By choosing to grow other native Hawaiian plants, supporting conservation organizations, and learning about rare species like this one, we all play a role in protecting Hawaii’s unique botanical heritage.

Sometimes the most important plants are the ones we admire from afar, knowing that their greatest value lies not in our gardens, but in the wild spaces they call home – if they still exist at all.

Necklace Island Spleenwort

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 leucostegioides (Baker) W.H. Wagner - necklace island spleenwort

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