North America Native Plant

Kauai Island-aster

Botanical name: Hesperomannia lydgatei

USDA symbol: HELY

Life cycle: perennial

Habit: tree

Native status: Native to Hawaii  

Kauai Island-Aster: A Critically Endangered Hawaiian Treasure Meet the Kauai island-aster (Hesperomannia lydgatei), one of Hawaii’s rarest native trees and a botanical treasure that’s hanging on by a thread. This remarkable member of the sunflower family represents both the incredible diversity of Hawaiian flora and the urgent conservation challenges facing ...

Rare plant alert!

Region: United States

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) ⚘ Endangered: In danger of extinction throughout all or a significant portion of its range. ⚘

Region: United States

Kauai Island-Aster: A Critically Endangered Hawaiian Treasure

Meet the Kauai island-aster (Hesperomannia lydgatei), one of Hawaii’s rarest native trees and a botanical treasure that’s hanging on by a thread. This remarkable member of the sunflower family represents both the incredible diversity of Hawaiian flora and the urgent conservation challenges facing island ecosystems.

What Makes This Plant Special

The Kauai island-aster is a perennial tree that typically grows 13-16 feet tall with a single trunk, though it can sometimes develop a shorter, multi-stemmed form depending on environmental conditions. As part of the aster family, it produces distinctive flowers that set it apart from other Hawaiian trees.

Where It Calls Home

This species is endemic to Hawaii, meaning it exists nowhere else on Earth. More specifically, it’s found only on the island of Kauai, making it one of the most geographically restricted plants in the Hawaiian Islands.

A Plant in Crisis

Important Conservation Alert: The Kauai island-aster has a Global Conservation Status of S1, which means it’s critically imperiled. With typically five or fewer occurrences and very few remaining individuals (less than 1,000), this species is classified as Endangered. This isn’t a plant you’ll find at your local nursery, nor should you attempt to collect it from the wild.

Growing Conditions and Habitat

In its natural habitat, the Kauai island-aster has a Facultative Upland status, meaning it usually grows in non-wetland areas but may occasionally be found in wetland conditions. The species requires very specific environmental conditions found only in its native Hawaiian ecosystem.

Can You Grow It?

Here’s the reality check: this isn’t a plant for home gardens. The Kauai island-aster requires highly specialized growing conditions that are nearly impossible to replicate outside its native habitat. More importantly, given its critically endangered status, any cultivation should only be attempted through legitimate conservation programs with responsibly sourced material.

Supporting Conservation Instead

Rather than trying to grow this rare beauty, consider supporting Hawaiian plant conservation efforts. Here are meaningful ways to help:

  • Support organizations working to protect Hawaiian native plants
  • Choose other native Hawaiian plants that are more readily available and less threatened
  • Learn about and share awareness of endangered Hawaiian flora
  • Visit botanical gardens that participate in conservation programs

The Bigger Picture

The Kauai island-aster serves as a reminder of what we stand to lose when ecosystems are threatened. Each rare plant like this one represents millions of years of evolution and adaptation to specific environmental conditions. While we may not be able to grow it in our gardens, we can certainly grow our appreciation for the incredible diversity of life that islands like Kauai support.

Sometimes the most beautiful way to honor a plant is to admire it from afar and work to ensure it continues to exist in its natural home for future generations to discover and wonder at.

Kauai Island-aster

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

Asterales

Family

Asteraceae Bercht. & J. Presl - Aster family

Genus

Hesperomannia A. Gray - island-aster

Species

Hesperomannia lydgatei Forbes - Kauai island-aster

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