North America Native Plant

Koolau Range Lobelia

Botanical name: Lobelia gaudichaudii koolauensis

USDA symbol: LOGAK3

Life cycle: perennial

Habit: subshrub

Native status: Native to Hawaii  

Synonyms: Lobelia gaudichaudii A. DC. var. koolauensis Hosaka & Fosberg (LOGAK2)  âš˜  Lobelia koolauensis (Hosaka & Fosberg) Lammers (LOKO3)   

Koolau Range Lobelia: A Precious Hawaiian Treasure in Need of Protection Meet the Koolau Range lobelia (Lobelia gaudichaudii koolauensis), one of Hawaii’s most endangered native plants. This remarkable little perennial herb holds a special place in the islands’ natural heritage, but it’s also a plant that comes with serious conservation ...

Rare plant alert!

Region: United States

Status: S1T1: 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) ⚘ Subspecies or variety is 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

Koolau Range Lobelia: A Precious Hawaiian Treasure in Need of Protection

Meet the Koolau Range lobelia (Lobelia gaudichaudii koolauensis), one of Hawaii’s most endangered native plants. This remarkable little perennial herb holds a special place in the islands’ natural heritage, but it’s also a plant that comes with serious conservation considerations for any gardener thinking about adding it to their landscape.

What Makes This Plant Special?

The Koolau Range lobelia is a true Hawaiian endemic, meaning it exists nowhere else on Earth except in its native home on Oahu’s Koolau Range. This perennial forb belongs to the diverse Hawaiian lobelia family, which has evolved into some of the most unique plant forms found anywhere in the Pacific.

Also known by its botanical synonyms Lobelia gaudichaudii var. koolauensis and Lobelia koolauensis, this plant represents thousands of years of evolution in Hawaii’s isolated mountain forests.

Where Does It Grow?

This lobelia is found exclusively in Hawaii, specifically in the cool, misty forests of Oahu’s Koolau Mountain Range. These high-elevation environments provide the perfect combination of humidity, temperature, and rainfall that this specialized plant needs to survive.

A Plant in Crisis

Important Conservation Alert: The Koolau Range lobelia is classified as Endangered with a Global Conservation Status of S1T1. This means the species is critically imperiled and faces a very high risk of extinction. As a responsible gardener, it’s crucial to understand that this plant should only be grown as part of authorized conservation efforts.

If you’re passionate about Hawaiian native plants, consider supporting conservation organizations rather than attempting to grow this species in your garden. There are other beautiful native Hawaiian plants that aren’t endangered and can fulfill similar roles in your landscape.

Growing Conditions and Habitat

In its natural habitat, the Koolau Range lobelia thrives as a facultative wetland plant, meaning it usually grows in wetland conditions but can occasionally be found in drier areas. The plant prefers:

  • Cool, humid mountain forest conditions
  • USDA hardiness zones 10-12 (specific to Hawaiian tropical climates)
  • High elevation environments with consistent moisture
  • Protection from strong winds and intense sun

Ecological Importance

Like many Hawaiian lobelias, this species likely evolved alongside native Hawaiian birds, particularly the Hawaiian honeycreepers, which may have served as its primary pollinators. The loss of both plant and bird species creates a tragic cycle that makes recovery even more challenging.

What You Can Do Instead

While you shouldn’t plant the endangered Koolau Range lobelia, you can still support Hawaiian native plant conservation by:

  • Choosing other native Hawaiian plants that aren’t endangered
  • Supporting local conservation organizations
  • Creating habitat for native Hawaiian wildlife
  • Learning about and sharing information about endangered species

The Bottom Line

The Koolau Range lobelia represents both the incredible biodiversity of Hawaii and the fragility of island ecosystems. While this beautiful native herb would be a treasure in any garden, its endangered status means it belongs in conservation programs rather than home landscapes. By respecting its protected status and supporting conservation efforts, we can help ensure that future generations will have the chance to appreciate this remarkable Hawaiian endemic.

Remember: the best way to honor endangered native plants is to protect them in their natural habitat while choosing sustainable alternatives for our gardens.

Koolau Range Lobelia

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

Lobelia L. - lobelia

Species

Lobelia gaudichaudii A. DC. - Koolau Range lobelia

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