Native Plants

Koolau Range Delissea

Delissea subcordata

USDA symbol: DESU

perennial shrub

Hawaii: native

If you’ve stumbled upon information about the Koolau Range delissea (Delissea subcordata), you’ve discovered one of Hawaii’s most precious and precarious native plants. This isn’t your typical gardening recommendation – in fact, it’s quite the opposite. Let me tell you why this remarkable shrub deserves our respect, protection, and distance. ...

Koolau Range Delissea may be listed as rare in your area.
Global Conservation Status

Status: S1 | Critically imperiled: Typically 5 or fewer occurrences or under 1,000 remaining individuals.

United States

Status: Endangered | Endangered. In danger of extinction throughout all or a significant portion of its range.

Koolau Range Delissea: A Critically Endangered Hawaiian Treasure

If you’ve stumbled upon information about the Koolau Range delissea (Delissea subcordata), you’ve discovered one of Hawaii’s most precious and precarious native plants. This isn’t your typical gardening recommendation – in fact, it’s quite the opposite. Let me tell you why this remarkable shrub deserves our respect, protection, and distance.

What Makes This Plant So Special?

The Koolau Range delissea is a native Hawaiian perennial shrub that belongs to the bellflower family. This multi-stemmed woody plant typically grows to heights of 13-16 feet, creating an impressive presence in its natural habitat. Found exclusively in Hawaii, this species carries the weight of millions of years of island evolution on its branches.

A Plant in Crisis

Here’s the crucial information every plant lover needs to know: Delissea subcordata has a Global Conservation Status of S1, meaning it’s critically imperiled. With typically five or fewer occurrences and very few remaining individuals (fewer than 1,000), this species is listed as Endangered in the United States.

What does this mean for you as a gardener? Simply put, this plant should not be in cultivation by amateur gardeners. Its rarity status makes it unsuitable for typical home gardens, and any cultivation should only be undertaken by qualified conservation professionals with proper permits and responsibly sourced material.

Where Does It Call Home?

As its common name suggests, the Koolau Range delissea is native to Hawaii, specifically associated with the Koolau mountain range. This plant has evolved to thrive in Hawaii’s unique island ecosystem, making it perfectly adapted to tropical conditions found in USDA hardiness zones 10-11.

  • Species observed
  • No observations

Why You Shouldn’t Plant It (And What to Plant Instead)

While the conservation story of this plant is fascinating, responsible gardening means recognizing when a plant is too rare for cultivation. Here’s what you should know:

  • Rarity: With so few individuals remaining, every plant is crucial for species survival
  • Legal protection: Endangered species often have legal protections that restrict collection and cultivation
  • Specialized needs: Critically endangered plants often have very specific growing requirements that are difficult to replicate
  • Conservation priority: Efforts should focus on habitat protection and professional breeding programs

Better Alternatives for Your Hawaiian Garden

If you’re passionate about native Hawaiian plants (and you should be!), consider these more readily available alternatives that won’t impact wild populations:

  • Other native Hawaiian shrubs that are more stable in the wild
  • Plants propagated through legitimate native plant societies
  • Species recommended by local botanical gardens and conservation organizations

How You Can Help Instead

Your love for native plants can make a real difference for species like the Koolau Range delissea:

  • Support Hawaiian plant conservation organizations
  • Visit botanical gardens that maintain conservation collections
  • Advocate for habitat protection in Hawaii
  • Choose other native Hawaiian plants for your garden that don’t impact wild populations
  • Educate others about the importance of plant conservation

The Bigger Picture

The story of Delissea subcordata is a reminder that not every beautiful plant belongs in our gardens. Sometimes the most loving thing we can do for a species is to admire it from afar and work to protect its wild habitat. Hawaii’s native flora faces tremendous pressure from habitat loss, invasive species, and climate change – and plants like the Koolau Range delissea represent irreplaceable pieces of natural heritage.

While you won’t be adding this particular shrub to your landscape, you can still be part of its conservation story by supporting the professionals working to save it and choosing garden plants that celebrate native biodiversity without putting rare species at risk.

Delissea subcordata is also known as...

Often we refer to plants by their common names. When shopping for plants the scientific name is the best way to positively identify the plant species you desire. But some plants have more than one name! While it doesn't happen often, nurseries might display one name while you're searching for another. Delissea subcordata is also known as:

Delissea subcordata var. kauaiensis | USDA symbol: DESUK
Delissea subcordata var. obtusifolia | USDA symbol: DESUO
Delissea subcordata var. waikaneensis | USDA symbol: DESUW
Delissea subcordata var. waralaeensis | USDA symbol: DESUW2

Why do some plants have more than one name? Over time plant species may be renamed for a few reasons:

  1. Botanists in different regions named the same plant without knowing it had already been classified.
  2. A species was reclassified after scientific advances in, for example, DNA analysis.
  3. Slight variations within a species are sometimes mistakenly identified as entirely new species.

Classification

Group: Dicot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Class: Magnoliopsida - Dicotyledons
Subclass: Asteridae
Order: Campanulales
Family: Campanulaceae Juss. - Bellflower family
Genus: Delissea Gaudich. - delissea

Species: Delissea subcordata Gaudich. - Koolau Range delissea

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