North America Native Plant

Delissea

Botanical name: Delissea niihauensis

USDA symbol: DENI

Life cycle: perennial

Habit: tree

Native status: Native to Hawaii  

Delissea: A Critically Endangered Hawaiian Tree Worth Knowing About Meet delissea (Delissea niihauensis), one of Hawaii’s rarest native trees and a true botanical treasure that’s teetering on the edge of extinction. While you probably won’t be adding this perennial beauty to your garden anytime soon, learning about this remarkable plant ...

Rare plant alert!

Region: Conservation status by state

Status: S1: Status is uncertain but is somewhere between the following rankings: 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) ⚘

Delissea: A Critically Endangered Hawaiian Tree Worth Knowing About

Meet delissea (Delissea niihauensis), one of Hawaii’s rarest native trees and a true botanical treasure that’s teetering on the edge of extinction. While you probably won’t be adding this perennial beauty to your garden anytime soon, learning about this remarkable plant helps us understand the incredible diversity—and fragility—of Hawaii’s native ecosystems.

What Makes Delissea Special?

This striking tree belongs to the bellflower family and represents one of nature’s most exclusive clubs. As a perennial woody plant, delissea typically grows as a single-stemmed tree reaching heights of 13-16 feet or more, though environmental conditions can sometimes result in shorter, multi-stemmed growth forms.

Where Does Delissea Call Home?

Delissea niihauensis is endemic to Hawaii, meaning it exists nowhere else on Earth. This native Hawaiian species has an extremely limited range, making it one of the state’s most geographically restricted plants.

The Reality Check: Why You Shouldn’t Plant This Tree

Here’s where things get serious. Delissea niihauensis carries a Global Conservation Status of S1, which translates to Critically Imperiled. This designation means:

  • Fewer than 5 known occurrences exist in the wild
  • Less than 1,000 individual plants remain
  • The species faces extreme vulnerability to extinction

Given this precarious status, delissea should only be grown through authorized conservation programs using responsibly sourced material. Attempting to collect or grow this plant without proper permits and expertise could inadvertently harm the remaining wild populations.

Growing Conditions (For Conservation Context)

While specific growing requirements remain largely undocumented, delissea would naturally thrive in:

  • Tropical Hawaiian climates (USDA zones 10-12)
  • Native Hawaiian forest ecosystems
  • Conditions that support other native Hawaiian flora

Supporting Conservation Efforts

Instead of trying to grow this rare beauty, consider supporting Hawaiian plant conservation through:

  • Donating to native plant preservation organizations
  • Choosing abundant native Hawaiian alternatives for your garden
  • Spreading awareness about Hawaii’s endangered flora

Native Alternatives to Consider

If you’re inspired by delissea’s story and want to support Hawaiian native plants in your garden, consider these more readily available options:

  • Other native Hawaiian trees that aren’t critically endangered
  • Native plants that support local pollinators and wildlife
  • Species that help restore Hawaiian ecosystems

Remember, every native plant we grow in our gardens—even the common ones—plays a vital role in preserving Hawaii’s unique botanical heritage. While we may not be able to cultivate delissea ourselves, we can honor its existence by protecting the native plants we can grow and supporting conservation efforts for those we cannot.

Delissea

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Campanulales

Family

Campanulaceae Juss. - Bellflower family

Genus

Delissea Gaudich. - delissea

Species

Delissea niihauensis H. St. John - delissea

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