North America Native Plant

Koolau Range Lobelia

Botanical name: Lobelia gaudichaudii gaudichaudii

USDA symbol: LOGAG2

Life cycle: perennial

Habit: subshrub

Native status: Native to Hawaii  

Koolau Range Lobelia: A Rare Hawaiian Treasure Worth Protecting If you’re dreaming of adding a touch of authentic Hawaiian flora to your garden, the Koolau Range lobelia might catch your eye. But before you start planning where to plant this beautiful native, there’s something important you need to know about ...

Rare plant alert!

Region: Conservation status by state

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) ⚘

Koolau Range Lobelia: A Rare Hawaiian Treasure Worth Protecting

If you’re dreaming of adding a touch of authentic Hawaiian flora to your garden, the Koolau Range lobelia might catch your eye. But before you start planning where to plant this beautiful native, there’s something important you need to know about this extraordinary little plant.

What Makes This Plant Special?

The Koolau Range lobelia (Lobelia gaudichaudii gaudichaudii) is a perennial herb that’s as rare as it is beautiful. This delicate forb grows naturally in Hawaii’s mesic to wet forests, where it produces charming small flowers that have been quietly blooming in island forests for countless generations.

As a true Hawaiian endemic, this lobelia has evolved specifically to thrive in the unique conditions of the Hawaiian Islands. It’s not just any garden plant – it’s a living piece of Hawaii’s natural heritage.

Where Does It Call Home?

This special lobelia is found exclusively in Hawaii, making it one of the state’s precious endemic species. Its natural habitat includes the mesic to wet forests of the Hawaiian Islands, where it grows as part of complex native ecosystems.

The Reality Check: Rarity Status

Here’s where things get serious. The Koolau Range lobelia has a Global Conservation Status of S1T1, which means it’s extremely rare and vulnerable. This isn’t a plant you’ll find at your local nursery, and for good reason – it needs our protection, not our gardening experiments.

If you’re considering adding this plant to your collection, please only work with reputable conservation organizations or specialized native plant societies that can provide responsibly sourced material.

Growing Conditions: Not for Beginners

Even if you could source this plant responsibly, growing the Koolau Range lobelia is no walk in the park. This Hawaiian native requires:

  • USDA Hardiness Zones 10-12 (tropical and subtropical climates only)
  • Partial shade conditions mimicking its forest habitat
  • Well-draining, organic-rich soil
  • Consistent moisture without waterlogging
  • Protection from strong winds
  • Specific humidity levels found in Hawaiian forests

Unless you live in Hawaii or have a specialized greenhouse setup, successfully growing this plant would be extremely challenging.

Wildlife and Pollinator Benefits

In its native habitat, the Koolau Range lobelia plays an important role in supporting Hawaii’s unique ecosystem. Native Hawaiian birds and insects have co-evolved with plants like this one, creating intricate relationships that have developed over thousands of years.

A Better Approach: Conservation Over Cultivation

Rather than trying to grow this rare beauty in your garden, consider supporting Hawaiian native plant conservation efforts instead. You can:

  • Donate to organizations working to protect Hawaiian endemic plants
  • Visit Hawaiian botanical gardens to see native plants in appropriate settings
  • Choose other Hawaiian natives that are less rare for your garden
  • Spread awareness about the importance of protecting endemic species

The Bottom Line

The Koolau Range lobelia is undoubtedly a fascinating plant, but it’s not meant for typical home gardens. Its extreme rarity and specialized growing requirements make it a plant that’s better appreciated and protected in its natural habitat or specialized conservation facilities.

If you’re passionate about Hawaiian native plants, there are other beautiful endemic species that are less rare and more suitable for cultivation. Focus on those, and leave this precious lobelia to the conservation experts who are working hard to ensure it doesn’t disappear from Hawaii’s forests forever.

Sometimes the best way to love a plant is to admire it from afar and support efforts to protect it in the wild.

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