North America Native Plant

Molokai False Lobelia

Botanical name: Trematolobelia rockii

USDA symbol: TRRO2

Life cycle: perennial

Habit: shrub

Native status: Native to Hawaii  

Molokai False Lobelia: A Rare Hawaiian Treasure If you’ve stumbled upon the name Molokai false lobelia while researching native Hawaiian plants, you’ve discovered one of the islands’ most elusive botanical treasures. This remarkable plant, scientifically known as Trematolobelia rockii, represents the incredible diversity and fragility of Hawaii’s native flora. What ...

Molokai False Lobelia: A Rare Hawaiian Treasure

If you’ve stumbled upon the name Molokai false lobelia while researching native Hawaiian plants, you’ve discovered one of the islands’ most elusive botanical treasures. This remarkable plant, scientifically known as Trematolobelia rockii, represents the incredible diversity and fragility of Hawaii’s native flora.

What Makes This Plant Special

The Molokai false lobelia is a perennial shrub that belongs to Hawaii’s unique endemic plant family. As a multi-stemmed woody plant, it typically grows to heights of 13-16 feet, though it can vary depending on environmental conditions. What makes this plant truly special isn’t just its growth pattern—it’s its incredible rarity and the story it tells about Hawaiian biodiversity.

Where It Calls Home

This plant is endemic to Hawaii, meaning it exists nowhere else on Earth. As its common name suggests, it’s particularly associated with the island of Molokai, where it evolved in isolation over thousands of years.

A Plant You Can’t (and Shouldn’t Try to) Grow

Here’s where things get serious, fellow plant enthusiasts. The Molokai false lobelia is extremely rare—so rare, in fact, that it may no longer exist in the wild. This isn’t a plant you can pick up at your local nursery, nor should you attempt to source it through other channels. Instead, this species serves as an important reminder about conservation and the fragility of island ecosystems.

Understanding Its Natural Habitat

Based on its wetland status as a Facultative Wetland plant, the Molokai false lobelia typically thrived in Hawaii’s wet environments, though it could also survive in drier conditions. This adaptability likely helped it survive in Hawaii’s diverse microclimates—at least for a while.

What We Can Learn

While you can’t grow this particular plant, its story teaches us valuable lessons:

  • Island endemic plants are incredibly vulnerable to habitat loss
  • Every native plant plays a crucial role in its ecosystem
  • Conservation efforts are essential for protecting rare species
  • Supporting native plant conservation organizations makes a real difference

Better Alternatives for Your Garden

If you’re inspired by Hawaiian native plants and want to support conservation through gardening, consider these alternatives that are actually available and appropriate for cultivation:

  • Other Hawaiian lobelias that are less endangered
  • Native Hawaiian shrubs suitable for your climate zone
  • Plants that support similar ecological functions

Always source native plants from reputable nurseries that practice ethical propagation and never collect from wild populations.

Supporting Conservation

The best way to honor plants like the Molokai false lobelia is to support Hawaiian plant conservation organizations and native habitat restoration projects. While we may not be able to grow this particular species in our gardens, we can contribute to efforts that protect what remains of Hawaii’s unique flora and work to restore damaged ecosystems.

Remember, sometimes the most responsible thing we can do as gardeners is to appreciate a plant from afar and focus our growing efforts on species that are abundant and ethically available. The Molokai false lobelia’s legacy lives on in the conservation work being done to protect Hawaii’s remaining native plants.

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

Molokai 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 rockii H. St. John - Molokai 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