Native Plants

Kohala False Lobelia

Trematolobelia wimmeri

USDA symbol: TRWI2

perennial tree

Hawaii: native

Meet the Kohala false lobelia (Trematolobelia wimmeri), a fascinating native Hawaiian tree that’s as unique as its tongue-twisting name suggests. This perennial beauty belongs to the lobelia family, but don’t expect your typical garden lobelia – this one grows into a proper tree that can tower over 13 feet tall! ...

Kohala False Lobelia: A Rare Hawaiian Tree Worth Preserving

Meet the Kohala false lobelia (Trematolobelia wimmeri), a fascinating native Hawaiian tree that’s as unique as its tongue-twisting name suggests. This perennial beauty belongs to the lobelia family, but don’t expect your typical garden lobelia – this one grows into a proper tree that can tower over 13 feet tall!

What Makes This Plant Special

The Kohala false lobelia is a true Hawaiian original, found nowhere else on Earth. As its common name hints, this species has strong ties to the Kohala region, making it a genuine piece of Hawaiian natural heritage. Like many Hawaiian endemics, it represents millions of years of evolution in isolation, developing characteristics found nowhere else in the world.

This perennial tree typically grows with a single trunk, though environmental conditions can sometimes encourage a more shrub-like, multi-stemmed growth pattern. While we don’t have specific details about its flowers, being part of the lobelia family suggests it likely produces distinctive tubular blooms that evolved alongside Hawaii’s native pollinators.

Where You’ll Find It Growing

Trematolobelia wimmeri calls Hawaii home exclusively, growing naturally only in the Hawaiian Islands. This limited geographic distribution makes it a true treasure of Hawaiian biodiversity.

  • Species observed
  • No observations

Garden and Landscape Potential

If you’re gardening in Hawaii and passionate about native plants, the Kohala false lobelia could be an incredible addition to your landscape – with some important caveats. This tree works beautifully as:

  • A specimen tree in native Hawaiian gardens
  • Part of conservation-focused landscaping projects
  • An educational feature in botanical gardens or nature centers
  • A component of habitat restoration efforts

However, this isn’t a plant for casual gardening. Its rarity and specific needs make it more suitable for serious native plant enthusiasts and conservation-minded gardeners.

Growing Conditions and Care

The Kohala false lobelia has facultative wetland status in Hawaii, meaning it can thrive in both wetland and non-wetland conditions. This adaptability is actually good news for gardeners, as it suggests some flexibility in planting locations.

For Hawaiian gardeners interested in growing this species, you’ll want to:

  • Provide conditions similar to its natural habitat
  • Ensure good drainage while maintaining consistent moisture
  • Choose a location with appropriate space for a tree that can exceed 13 feet
  • Consider the long-term commitment – this is a perennial tree species

Those gardening outside Hawaii should note that this species is adapted to tropical conditions and won’t survive in temperate climates.

A Word About Conservation

Here’s where things get serious: if you’re considering adding Kohala false lobelia to your garden, please ensure you’re sourcing it responsibly. Many Hawaiian endemic plants face conservation challenges, and removing plants from wild populations can harm already vulnerable species.

Always purchase from reputable native plant nurseries that propagate their stock rather than collecting from the wild. Better yet, consider supporting conservation efforts for this species through donations or volunteer work with Hawaiian native plant organizations.

The Bottom Line

The Kohala false lobelia represents something truly special – a piece of Hawaii’s unique natural heritage that exists nowhere else on our planet. While it may not be the easiest plant to grow or find, for the right gardener in the right location, it offers the chance to participate in preserving Hawaii’s irreplaceable botanical legacy.

If you’re not in Hawaii, consider this plant an inspiration to explore and support the native species in your own region. Every ecosystem has its own treasures worth celebrating and protecting.

Trematolobelia wimmeri is also known as...

Often we refer to plants by their common names. When shopping for plants the scientific name is the best way to positively identify the plant species you desire. But some plants have more than one name! While it doesn't happen often, nurseries might display one name while you're searching for another. Trematolobelia wimmeri is also known as:

Trematolobelia kohalaensis | USDA symbol: TRKO
Trematolobelia lustrialis | USDA symbol: TRLU7
Trematolobelia rockii John var. hawaiiensis | USDA symbol: TRROH

Why do some plants have more than one name? Over time plant species may be renamed for a few reasons:

  1. Botanists in different regions named the same plant without knowing it had already been classified.
  2. A species was reclassified after scientific advances in, for example, DNA analysis.
  3. Slight variations within a species are sometimes mistakenly identified as entirely new species.

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 care and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection can be if you don't have the right information. While tags on nursery plants 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. You might be surprised to learn that popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. The table below gives insight into the preferred growing conditions of this plant throughout its geographical distribution.

Region
Preferred Habitat

Hawaii ()

Facultative
Wetland Glossary
Obligate Wetland
Facultative Wetland
Facultative
Facultative Upland
Obligate Upland
Almost always occurs in wetlands
Usually occurs in wetlands but may occur in non-wetlands
Can occur in wetlands and non-wetlands
Usually occurs in non-wetlands but may occur in wetlands
Almost never occurs in wetlands

Classification

Group: Dicot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Class: Magnoliopsida - Dicotyledons
Subclass: Asteridae
Order: Campanulales
Family: Campanulaceae Juss. - Bellflower family
Genus: Trematolobelia Zahlbr. ex Rock - false lobelia

Species: Trematolobelia wimmeri O. Deg. & I. Deg. - Kohala 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