North America Native Plant

Laupahoehoe Phyllostegia

Botanical name: Phyllostegia warshaueri

USDA symbol: PHWA3

Life cycle: perennial

Habit: vine

Native status: Native to Hawaii  

Synonyms: Phyllostegia brevidens A. Gray var. longipes (Hillebr.) Sherff (PHBRL)   

Laupahoehoe Phyllostegia: A Rare Hawaiian Native Worth Protecting Meet one of Hawaii’s most endangered native plants – the Laupahoehoe phyllostegia (Phyllostegia warshaueri). This charming member of the mint family might not be a household name, but it deserves a spot in every conservation-minded gardener’s heart. With its delicate flowers and ...

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

Laupahoehoe Phyllostegia: A Rare Hawaiian Native Worth Protecting

Meet one of Hawaii’s most endangered native plants – the Laupahoehoe phyllostegia (Phyllostegia warshaueri). This charming member of the mint family might not be a household name, but it deserves a spot in every conservation-minded gardener’s heart. With its delicate flowers and climbing habit, this perennial vine represents both the beauty and fragility of Hawaii’s unique flora.

What Makes This Plant Special

The Laupahoehoe phyllostegia is a twining, climbing plant that can develop both woody and herbaceous stems as it matures. True to its mint family heritage, it produces small, tubular flowers that range from white to pale purple. The plant’s climbing nature makes it an excellent choice for adding vertical interest to native Hawaiian gardens, where it can gracefully wind through other vegetation or climb provided supports.

Where It Calls Home

This remarkable plant is endemic to Hawaii, meaning it exists nowhere else on Earth. Its distribution is extremely limited within the Hawaiian Islands, making every individual plant precious for the ecosystem’s biodiversity.

A Plant in Crisis

Important Conservation Note: The Laupahoehoe phyllostegia carries a Global Conservation Status of S1, meaning it’s critically imperiled with typically five or fewer occurrences remaining in the wild. In the United States, it’s classified as Endangered. This isn’t just a number – it’s a urgent call for action.

If you’re considering growing this plant, you absolutely must source it responsibly from:

  • Certified native plant nurseries specializing in Hawaiian species
  • Botanical gardens with legitimate propagation programs
  • Conservation organizations working to preserve the species

Never collect this plant from the wild – doing so could push it closer to extinction.

Growing Conditions and Care

The Laupahoehoe phyllostegia thrives in Hawaii’s tropical climate (USDA hardiness zones 10-11) and has specific needs that reflect its natural habitat:

  • Light: Partial shade to filtered sunlight
  • Soil: Well-draining but consistently moist soil
  • Water: Regular watering to maintain soil moisture
  • Humidity: High humidity levels typical of Hawaiian environments
  • Support: Provide trellises, poles, or other plants for climbing

According to its wetland status, this plant is facultative upland, meaning it usually grows in non-wetland areas but can tolerate some wetland conditions. This flexibility makes it adaptable to various moisture levels in your garden.

Perfect Garden Companions

The Laupahoehoe phyllostegia shines in:

  • Native Hawaiian landscape designs
  • Conservation gardens focused on endangered species
  • Specialized collections for plant enthusiasts
  • Educational gardens highlighting Hawaii’s unique flora

Its climbing habit makes it an excellent choice for adding layers to your garden design, and its mint family flowers likely attract native Hawaiian pollinators and beneficial insects.

Why Grow This Rare Beauty?

Growing the Laupahoehoe phyllostegia isn’t just about adding an unusual plant to your collection – it’s about participating in conservation. By cultivating this species responsibly, you’re:

  • Supporting genetic diversity outside of wild populations
  • Raising awareness about Hawaii’s endangered flora
  • Contributing to potential future restoration efforts
  • Connecting with Hawaii’s natural heritage

The Bottom Line

The Laupahoehoe phyllostegia represents both opportunity and responsibility. While its rarity makes it a challenging plant to obtain, those who can source it ethically will be rewarded with a unique piece of Hawaii’s natural heritage. Remember: with great rarity comes great responsibility. This isn’t a plant for casual collecting – it’s a species that needs our protection and respect.

If you can’t source this plant responsibly, consider supporting the organizations working to protect it, or focus on other native Hawaiian plants that aren’t quite so critically endangered. Every native plant we grow helps preserve the islands’ incredible botanical legacy.

Laupahoehoe Phyllostegia

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

Phyllostegia Benth. - phyllostegia

Species

Phyllostegia warshaueri H. St. John - Laupahoehoe phyllostegia

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