North America Native Plant

Spleenwort

Botanical name: Asplenium ×sphenocookii

USDA symbol: ASSP19

Life cycle: perennial

Habit: forb

Native status: Native to Hawaii  

The Mysterious Hawaiian Spleenwort: Asplenium ×sphenocookii If you’re a fern enthusiast with a taste for the rare and unusual, you might have stumbled across the intriguing name Asplenium ×sphenocookii. This Hawaiian native spleenwort is one of those botanical mysteries that makes plant lovers do a double-take – and for good ...

The Mysterious Hawaiian Spleenwort: Asplenium ×sphenocookii

If you’re a fern enthusiast with a taste for the rare and unusual, you might have stumbled across the intriguing name Asplenium ×sphenocookii. This Hawaiian native spleenwort is one of those botanical mysteries that makes plant lovers do a double-take – and for good reason!

What Exactly Is This Fern?

Asplenium ×sphenocookii is a hybrid spleenwort that calls the beautiful Hawaiian islands home. The little × symbol in its name is your first clue that this isn’t your garden-variety fern – it’s actually a natural hybrid, meaning it’s the result of two different Asplenium species getting together and creating something entirely new.

As a perennial fern, this plant would theoretically stick around year after year in the right conditions, but here’s where things get interesting (and a bit frustrating for curious gardeners): this particular hybrid is quite the enigma in the plant world.

Where You’ll Find It

This spleenwort is exclusively native to Hawaii, making it a true island endemic. You won’t find this little guy growing wild anywhere else in the world – Hawaii is its one and only home.

The Garden Reality Check

Now, here’s where we need to have a heart-to-heart about this fern. While Asplenium ×sphenocookii sounds absolutely fascinating, the truth is that very little specific information is available about this particular hybrid. It’s not readily available in the nursery trade, and its exact growing requirements, appearance, and garden performance remain largely undocumented.

For most gardeners, especially those outside of Hawaii, this fern remains more of a botanical curiosity than a practical garden choice. Its wetland status as Facultative Upland tells us it usually prefers non-wetland conditions but can tolerate some moisture – but that’s about all we know for certain about its preferences.

Is It Beneficial for Gardens?

While we can’t speak specifically to this hybrid’s garden benefits, ferns in general are wonderful additions to shady garden spaces. They:

  • Provide lush, green texture in low-light areas
  • Help create a sense of calm and tranquility
  • Often require minimal maintenance once established
  • Add architectural interest with their distinctive fronds

Better Alternatives for Your Garden

If you’re drawn to the idea of growing Hawaiian native ferns or spleenworts in general, consider looking for other, more readily available Asplenium species that are better documented and easier to source. Many other spleenworts offer the same elegant, feathery foliage and shade tolerance that make ferns such beloved garden plants.

For gardeners outside Hawaii, focusing on native ferns from your own region will give you the best chance of success while supporting local ecosystems. Your local native plant society can point you toward spleenworts and other ferns that will thrive in your specific climate and conditions.

The Bottom Line

Asplenium ×sphenocookii remains one of those plants that’s more interesting to read about than to actually grow. Its hybrid nature and limited documentation make it a challenging choice for home gardeners, and its Hawaiian-only native range means it’s not suited for cultivation in most locations anyway.

Sometimes the most fascinating plants are the ones that remind us that not everything in nature needs to end up in our gardens – and that’s perfectly okay! This mysterious Hawaiian spleenwort can continue to intrigue botanists and plant enthusiasts from afar while we focus on growing the many wonderful, well-documented ferns that are readily available for our own garden adventures.

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

FACU

Facultative Upland - Plants with this status usually occurs in non-wetlands but may occur in wetlands

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

Asplenium L. - spleenwort

Species

Asplenium ×sphenocookii W.H. Wagner [cookii × insiticium] - spleenwort

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