North America Native Plant

Lanai False Lobelia

Botanical name: Trematolobelia auriculata

USDA symbol: TRAU5

Life cycle: perennial

Habit: tree

Native status: Native to Hawaii  

Lanai False Lobelia: Hawaii’s Towering Native Treasure Meet one of Hawaii’s most unusual native plants – the Lanai false lobelia (Trematolobelia auriculata). This isn’t your garden-variety lobelia! While most lobelias are small flowering plants, this Hawaiian endemic breaks all the rules by growing into an impressive tree that can tower ...

Lanai False Lobelia: Hawaii’s Towering Native Treasure

Meet one of Hawaii’s most unusual native plants – the Lanai false lobelia (Trematolobelia auriculata). This isn’t your garden-variety lobelia! While most lobelias are small flowering plants, this Hawaiian endemic breaks all the rules by growing into an impressive tree that can tower over 13 feet tall.

A Plant Like No Other

The Lanai false lobelia is a true botanical oddity. As a perennial woody plant, it develops a single trunk and can reach heights of 13-16 feet or more, making it one of the most distinctive members of the lobelia family. Its large, lobed leaves and tree-like stature give it an almost prehistoric appearance that’s sure to be a conversation starter in any garden.

Where It Calls Home

This remarkable plant is native exclusively to Hawaii, with its primary home being the island of Lanai. As an endemic species, it represents millions of years of isolated evolution in the Hawaiian archipelago.

Why You Might (or Might Not) Want to Grow It

Reasons to consider it:

  • Unique architectural presence unlike any other plant
  • Supports native Hawaiian ecosystem restoration
  • Fascinating conversation piece for plant enthusiasts
  • Cultural and ecological significance

Important considerations:

  • Extremely limited natural range suggests potential rarity
  • Requires very specific growing conditions
  • May be difficult or impossible to source responsibly
  • Needs tropical/subtropical climate (USDA zones 10-11)

Growing Conditions and Care

If you’re fortunate enough to obtain this species through responsible channels, here’s what it needs to thrive:

Climate Requirements: Only suitable for USDA hardiness zones 10-11. This plant needs consistent warmth and humidity year-round.

Water Needs: As a facultative wetland plant, the Lanai false lobelia prefers consistently moist but well-draining soil. It can tolerate some variation in moisture levels but performs best with regular watering.

Light Requirements: Provide partial shade to filtered sunlight. In its native habitat, it typically grows under the canopy of other vegetation.

Soil Preferences: Well-draining, organic-rich soil that retains some moisture. A mix that mimics Hawaiian volcanic soils would be ideal.

A Word of Caution

Given its extremely limited native range on Lanai island, this species may be rare or endangered. If you’re interested in growing Trematolobelia auriculata, please ensure any plants are sourced through legitimate botanical institutions or conservation programs. Never collect plants from the wild, and always verify that your source is contributing to conservation efforts rather than depleting wild populations.

The Bottom Line

The Lanai false lobelia is a truly special plant that offers a unique opportunity to grow a piece of Hawaiian natural heritage. However, its specialized needs and potential rarity mean it’s best suited for dedicated native plant enthusiasts with the right climate and commitment to proper care. If you can’t access this species responsibly, consider supporting Hawaiian native plant conservation efforts or exploring other native Hawaiian species that may be more readily available through ethical sources.

For most gardeners, this remarkable tree-lobelia will remain a fascinating species to admire and learn about, representing the incredible diversity and uniqueness of Hawaii’s native flora.

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

FACW

Facultative Wetland - Plants with this status usually occurs in wetlands but may occur in non-wetlands

Lanai False 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

Trematolobelia Zahlbr. ex Rock - false lobelia

Species

Trematolobelia auriculata H. St. John - Lanai false lobelia

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