North America Native Plant

Waihanau Lobelia

Botanical name: Lobelia dunbarii

USDA symbol: LODU2

Life cycle: perennial

Habit: shrub

Native status: Native to Hawaii  

Waihanau Lobelia: A Rare Hawaiian Treasure You Can’t (and Shouldn’t) Grow If you’ve stumbled upon the name Waihanau lobelia (Lobelia dunbarii) while researching native Hawaiian plants for your garden, you’ve discovered one of Hawaii’s most elusive botanical treasures. But before you start planning where to plant this perennial shrub, there’s ...

Waihanau Lobelia: A Rare Hawaiian Treasure You Can’t (and Shouldn’t) Grow

If you’ve stumbled upon the name Waihanau lobelia (Lobelia dunbarii) while researching native Hawaiian plants for your garden, you’ve discovered one of Hawaii’s most elusive botanical treasures. But before you start planning where to plant this perennial shrub, there’s something important you need to know – this isn’t a plant you can simply pick up at your local nursery.

What Makes Waihanau Lobelia Special

Waihanau lobelia is a perennial shrub that’s exclusively native to Hawaii. Like many Hawaiian endemic species, it represents millions of years of isolated evolution, developing unique characteristics found nowhere else on Earth. This multi-stemmed woody plant typically grows less than 13 to 16 feet in height, with several stems arising from or near the ground – though it can sometimes grow taller or develop a single stem depending on environmental conditions.

Where Does It Call Home?

This endemic beauty is found only in Hawaii, making it part of the islands’ incredibly diverse but fragile native ecosystem. As a facultative wetland plant, Waihanau lobelia can survive in both wetland and non-wetland environments, giving it some flexibility in where it can establish itself.

The Reality Check: Why You Can’t Grow This One

Here’s where things get a bit sobering. Lobelia dunbarii appears to be extremely rare, with very little information available about its current status, cultivation requirements, or even recent sightings. This rarity means several things for gardeners:

  • It’s likely not available through any commercial sources
  • Its growing requirements remain largely unknown
  • It may be protected by conservation laws
  • Any existing plants need to remain in their natural habitat for species survival

What This Means for Your Garden

While you can’t grow Waihanau lobelia, its story highlights the importance of supporting native Hawaiian plant conservation. Instead of seeking out this rare species, consider these alternatives that can bring similar beauty to your Hawaiian landscape:

  • Other Lobelia species that are more readily available
  • Native Hawaiian shrubs with similar growth habits
  • Plants that support local pollinators and wildlife

Supporting Conservation Instead

Rather than trying to cultivate rare species like Waihanau lobelia, the best way to honor these plants is by:

  • Supporting local conservation organizations
  • Choosing readily available native Hawaiian plants for your garden
  • Learning about and sharing knowledge of Hawaii’s unique flora
  • Participating in habitat restoration projects

The Bigger Picture

Lobelia dunbarii serves as a reminder of how precious and fragile Hawaii’s native ecosystems are. While we can’t bring this particular plant into our gardens, we can create landscapes that celebrate Hawaiian biodiversity using species that are both available and appropriate for cultivation.

Sometimes the most respectful thing we can do as gardeners is to admire rare plants from afar and focus our green thumbs on species that can thrive in cultivation while still supporting native ecosystems. Your local native plant society or botanical garden can point you toward beautiful Hawaiian natives that are perfect for home gardens and won’t put rare species at risk.

Wetland Status

The rule of seasoned gardeners and landscapers is to choose the "right plant for the right place" matching plants to their ideal growing conditions, so they'll thrive with less work and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection is. While tags list watering requirements, there's more to the story.

Knowing a plant's wetland status can simplify the process by revealing the interaction between plants, water, and soil. Surprisingly, many popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. Also, it helps you make smarter gardening choices and grow healthy plants with less care and feeding, saving you time, frustration, and money while producing an attractive garden with greater ecological benefits.

Regions
Status
Moisture Conditions

Hawaii

FAC

Facultative - Plants with this status can occur in wetlands and non-wetlands

Waihanau 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 dunbarii Rock - Waihanau lobelia

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