North America Native Plant

Kauai Geranium

Botanical name: Geranium kauaiense

USDA symbol: GEKA

Life cycle: perennial

Habit: subshrub

Native status: Native to Hawaii  

Synonyms: Geranium humile Hillebr. var. kauaiense Rock (GEHUK)  âš˜  Geranium humile Hillebr. ssp. kauaiense (Rock) Carlq. & Bissing (GEHUK2)   

Kauai Geranium: A Rare Hawaiian Treasure Worth Protecting Meet the Kauai geranium (Geranium kauaiense), one of Hawaii’s most precious and endangered native plants. This isn’t your typical garden-variety geranium – it’s a critically rare shrub that calls the wetlands of Kauai home and desperately needs our protection. What Makes the ...

Rare plant alert!

Region: United States

Status: S1: 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) ⚘ Endangered: In danger of extinction throughout all or a significant portion of its range. ⚘

Region: United States

Kauai Geranium: A Rare Hawaiian Treasure Worth Protecting

Meet the Kauai geranium (Geranium kauaiense), one of Hawaii’s most precious and endangered native plants. This isn’t your typical garden-variety geranium – it’s a critically rare shrub that calls the wetlands of Kauai home and desperately needs our protection.

What Makes the Kauai Geranium Special

The Kauai geranium is a perennial shrub that typically grows as a multi-stemmed woody plant, usually staying under 13-16 feet in height. Unlike many plants that can adapt to various conditions, this particular geranium is what botanists call an obligate wetland species, meaning it almost always occurs in wetland environments.

You might also see this plant referenced by its scientific synonyms: Geranium humile var. kauaiense or Geranium humile ssp. kauaiense, but regardless of the name, we’re talking about the same incredibly rare plant.

Where Does It Call Home

This endemic Hawaiian species is found only in the state of Hawaii, specifically on the island of Kauai. It’s a true island native that has evolved to thrive in Hawaii’s unique wetland ecosystems over thousands of years.

A Plant in Crisis

Here’s where things get serious: the Kauai geranium has a Global Conservation Status of S1, which means it’s critically imperiled. In plain terms, this means there are typically five or fewer occurrences of this plant in the wild, with very few remaining individuals – we’re talking fewer than 1,000 plants total. It’s officially listed as Endangered in the United States.

This level of rarity puts the Kauai geranium in the same category as some of the world’s most threatened species. Every individual plant matters when you’re dealing with numbers this small.

Should You Plant Kauai Geranium

The short answer is: probably not, and here’s why. Given its critically endangered status, the Kauai geranium should only be grown through official conservation programs or with material that has been responsibly sourced through proper channels. This isn’t a plant you’ll find at your local nursery, nor should it be.

If you’re passionate about supporting this species, consider:

  • Supporting Hawaiian native plant conservation organizations
  • Participating in habitat restoration efforts
  • Choosing other native Hawaiian plants for your garden that aren’t endangered
  • Donating to botanical gardens or conservation programs working to protect rare species

Growing Conditions and Care

For those involved in legitimate conservation efforts, it’s important to understand that the Kauai geranium is extremely specialized. As an obligate wetland species, it requires consistently moist to wet soil conditions that mimic its natural wetland habitat. It’s adapted to Hawaii’s tropical climate, likely thriving in USDA hardiness zones 10-11.

The plant’s natural growing conditions include:

  • Wetland environments with consistent moisture
  • Tropical Hawaiian climate conditions
  • Specific soil types found in Kauai’s native wetlands
  • Natural plant communities that have co-evolved over millennia

The Bigger Picture

The Kauai geranium represents something bigger than just one rare plant – it’s a symbol of Hawaii’s unique biodiversity and the challenges facing island ecosystems. When we protect species like this, we’re preserving genetic diversity that took thousands of years to develop and could be lost forever in our lifetime.

While you might not be able to grow a Kauai geranium in your backyard, you can still make a difference. Choose native Hawaiian plants that aren’t endangered for your garden, support conservation efforts, and spread awareness about the importance of protecting our rarest species.

Sometimes the best way to love a plant is to appreciate it from afar and ensure it has a future in the wild where it belongs.

Kauai Geranium

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Rosidae

Order

Geraniales

Family

Geraniaceae Juss. - Geranium family

Genus

Geranium L. - geranium

Species

Geranium kauaiense (Rock) H. St. John - Kauai geranium

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