North America Native Plant

Cutleaf Island Spleenwort

Botanical name: Diellia laciniata

USDA symbol: DILA7

Life cycle: perennial

Habit: forb

Native status: Native to Hawaii  

Cutleaf Island Spleenwort: A Rare Hawaiian Fern for Dedicated Shade Gardeners If you’re drawn to delicate, lacy foliage and have a passion for rare native plants, the cutleaf island spleenwort (Diellia laciniata) might just capture your heart. This enchanting Hawaiian fern brings an air of tropical elegance to shaded gardens, ...

Rare plant alert!

Region: Conservation status by state

Status: S1Q: Status is uncertain but is somewhere between the following rankings: Uncertain taxonomy: ⚘ Critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘

Cutleaf Island Spleenwort: A Rare Hawaiian Fern for Dedicated Shade Gardeners

If you’re drawn to delicate, lacy foliage and have a passion for rare native plants, the cutleaf island spleenwort (Diellia laciniata) might just capture your heart. This enchanting Hawaiian fern brings an air of tropical elegance to shaded gardens, though its rarity means it’s not for every gardener.

What Makes This Fern Special?

The cutleaf island spleenwort is a perennial fern native exclusively to Hawaii, where it graces the understory of mesic to wet forests. True to its name, this beauty sports deeply divided, almost lace-like fronds that create intricate patterns of light and shadow. As a forb-type plant, it maintains a soft, herbaceous texture without developing woody stems, making it perfect for creating gentle contrast in shade gardens.

Where Does It Grow Naturally?

This Hawaiian endemic calls only the islands of Hawaii home, where it thrives in the filtered light of native forests. You’ll find it nestled among other native understory plants, taking advantage of the islands’ naturally humid, temperate conditions.

A Word of Caution: Rarity Matters

Here’s something every responsible gardener should know: cutleaf island spleenwort has a Global Conservation Status of S1Q, indicating it’s quite rare and its status needs further study. If you’re considering adding this fern to your collection, please ensure you source it only from reputable nurseries that propagate it responsibly. Never harvest from wild populations – this gorgeous fern needs our protection, not our exploitation.

Is This Fern Right for Your Garden?

This Hawaiian beauty thrives in USDA hardiness zones 10-12, making it suitable primarily for tropical and subtropical climates. It’s an excellent choice if you:

  • Live in a warm, humid climate year-round
  • Have shaded to partially shaded areas in your landscape
  • Want to create an authentic Hawaiian native garden
  • Appreciate delicate, intricate foliage textures
  • Are committed to responsible rare plant stewardship

Growing Conditions and Care

Like most forest understory plants, cutleaf island spleenwort prefers life in the shadows. Here’s what it needs to thrive:

  • Light: Shade to partial shade – direct sunlight will stress this delicate fern
  • Soil: Moist, well-draining soil rich in organic matter
  • Humidity: High humidity levels, similar to its native forest habitat
  • Water: Consistent moisture without waterlogging
  • Temperature: Warm temperatures year-round (zones 10-12)

Planting and Care Tips

Successfully growing this rare fern requires attention to detail:

  • Plant in a sheltered location protected from wind and direct sun
  • Amend soil with plenty of organic matter to retain moisture while ensuring drainage
  • Maintain consistent soil moisture – never let it completely dry out
  • Consider growing in containers if your climate is borderline suitable
  • Provide extra humidity through misting or grouping with other moisture-loving plants

Wildlife and Pollinator Benefits

As a fern, cutleaf island spleenwort doesn’t produce flowers or nectar, so it won’t directly attract pollinators. However, it can provide habitat and shelter for small insects and contribute to the overall ecosystem health of a native Hawaiian landscape design.

The Bottom Line

Cutleaf island spleenwort is a stunning addition to shade gardens in suitable climates, but it’s not a plant for casual gardeners. Its rarity demands responsible sourcing and dedicated care. If you’re passionate about Hawaiian native plants and can provide the specific conditions this fern needs, it will reward you with its delicate beauty. Just remember – with rare plants comes great responsibility.

Cutleaf 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 laciniata (Hillebr.) Diels - cutleaf 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