North America Native Plant

Hawai’i Stenogyne

Botanical name: Stenogyne macrantha

USDA symbol: STMA3

Life cycle: perennial

Habit: vine

Native status: Native to Hawaii  

Synonyms: Stenogyne macrantha Benth. var. grayi H. Mann (STMAG2)  âš˜  Stenogyne macrantha Benth. var. latifolia Hillebr. (STMAL)   

Hawai’i Stenogyne: A Rare Hawaiian Native Worth Preserving in Your Garden Meet the Hawai’i stenogyne (Stenogyne macrantha), a charming little Hawaiian native that’s as rare as it is beautiful. This delicate perennial herb might not be the showiest plant in the garden, but it carries the special distinction of being ...

Rare plant alert!

Region: Conservation status by state

Status: S2: Status is uncertain but is somewhere between the following rankings: Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘

Hawai’i Stenogyne: A Rare Hawaiian Native Worth Preserving in Your Garden

Meet the Hawai’i stenogyne (Stenogyne macrantha), a charming little Hawaiian native that’s as rare as it is beautiful. This delicate perennial herb might not be the showiest plant in the garden, but it carries the special distinction of being truly endemic to the Hawaiian Islands – meaning you won’t find it growing wild anywhere else on Earth.

What Makes This Plant Special

The Hawai’i stenogyne is a member of the mint family, though you might not guess it at first glance. This low-growing perennial herb produces small, tubular flowers that range from white to pale purple, creating a subtle but lovely display against its heart-shaped, serrated leaves. As a forb herb, it lacks the woody stems of shrubs and trees, instead growing as a soft, herbaceous plant that hugs close to the ground.

Where It Calls Home

This special plant is found exclusively in Hawaii, where it grows naturally on the islands of Kauai, Oahu, Molokai, and Maui. You’ll typically find it in upland areas rather than wetlands, as it prefers well-draining soils and can handle drier conditions once established.

A Conservation Concern

Here’s something important to know: the Hawai’i stenogyne is considered imperiled, with a Global Conservation Status of S2. This means there are typically only 6 to 20 known occurrences in the wild, with fewer than 1,000 to 3,000 individual plants remaining. This rarity makes it especially vulnerable to extinction, so if you’re thinking about adding this plant to your garden, it’s crucial to source it responsibly from reputable native plant nurseries or conservation programs – never from the wild.

Why Grow Hawai’i Stenogyne?

Despite its rarity (or perhaps because of it), there are compelling reasons to consider growing this native Hawaiian treasure:

  • Support conservation efforts by growing rare native plants
  • Create authentic Hawaiian landscapes with truly endemic species
  • Attract native Hawaiian insects and other pollinators
  • Enjoy a low-maintenance ground cover once established
  • Connect with Hawaii’s unique botanical heritage

Growing Conditions and Care

The Hawai’i stenogyne is surprisingly adaptable for such a rare plant, but it does have some specific preferences:

Climate Requirements

This tropical native thrives in USDA hardiness zones 10-12, making it suitable for year-round outdoor growing only in Hawaii, southern Florida, and similar tropical climates.

Light and Soil

Give your Hawai’i stenogyne partial shade to full sun and well-draining soil. The most important factor is drainage – this plant absolutely cannot tolerate waterlogged conditions. A rocky or sandy soil mix works well, mimicking its natural upland habitat.

Watering

Once established, this drought-tolerant native needs minimal supplemental watering. Water deeply but infrequently, allowing the soil to dry out between waterings. Overwatering is one of the fastest ways to kill this plant.

Garden Design Ideas

The Hawai’i stenogyne works beautifully in:

  • Native Hawaiian restoration gardens
  • Rock gardens and xeriscapes
  • Ground cover plantings in dry areas
  • Container gardens with excellent drainage
  • Educational or botanical gardens focusing on rare plants

A Word of Caution and Responsibility

Given its imperiled status, growing Hawai’i stenogyne comes with responsibility. Only obtain plants or seeds from legitimate conservation nurseries or programs. Never collect from wild populations, and consider participating in seed collection or propagation programs if available in your area. By growing this rare native responsibly, you’re not just adding a unique plant to your garden – you’re participating in conservation efforts to preserve Hawaii’s irreplaceable botanical heritage.

The Hawai’i stenogyne may be small and subtle, but it represents something much larger: the unique evolutionary story of the Hawaiian Islands and our collective responsibility to protect these irreplaceable treasures for future generations.

Hawai’i Stenogyne

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

Lamiales

Family

Lamiaceae Martinov - Mint family

Genus

Stenogyne Benth. - stenogyne

Species

Stenogyne macrantha Benth. - Hawai'i stenogyne

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