North America Native Plant

Largeleaf Phyllostegia

Botanical name: Phyllostegia macrophylla

USDA symbol: PHMA11

Life cycle: perennial

Habit: vine

Native status: Native to Hawaii  

Synonyms: Phyllostegia macrophylla (Gaudich.) Benth. var. phytolaccoides Sherff (PHMAP2)  âš˜  Phyllostegia macrophylla (Gaudich.) Benth. var. remyi Sherff (PHMAR)   

Largeleaf Phyllostegia: A Rare Hawaiian Treasure for Your Native Garden If you’re passionate about Hawaiian native plants and conservation gardening, you may have heard whispers about largeleaf phyllostegia (Phyllostegia macrophylla). This enchanting member of the mint family is one of Hawaii’s botanical gems – but it’s also one that requires ...

Rare plant alert!

Region: Conservation status by state

Status: S3: Status is uncertain but is somewhere between the following rankings: Vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals ⚘

Largeleaf Phyllostegia: A Rare Hawaiian Treasure for Your Native Garden

If you’re passionate about Hawaiian native plants and conservation gardening, you may have heard whispers about largeleaf phyllostegia (Phyllostegia macrophylla). This enchanting member of the mint family is one of Hawaii’s botanical gems – but it’s also one that requires our careful stewardship.

What Makes Largeleaf Phyllostegia Special?

Largeleaf phyllostegia is a perennial herb that’s completely native to Hawaii, found nowhere else in the world. As its name suggests, this plant is distinguished by its notably large leaves compared to its phyllostegia relatives. Like other members of the mint family, it produces small, tubular flowers that are perfectly adapted to Hawaii’s native pollinators.

This isn’t your typical backyard mint, though. Largeleaf phyllostegia is what botanists call a forb – essentially a soft-stemmed plant without woody tissue that dies back to ground level but returns year after year from its root system.

Where Does It Grow?

Largeleaf phyllostegia is endemic to the Hawaiian Islands, meaning it evolved here and exists naturally nowhere else on Earth. You’ll find it scattered across several of Hawaii’s islands, typically growing in forest understories and partially shaded areas.

A Plant That Needs Our Help

Important Conservation Note: Before we dive into growing tips, there’s something crucial you need to know. Largeleaf phyllostegia has a Global Conservation Status of S3, which means it’s considered Vulnerable. With only an estimated 21-100 occurrences and between 3,000-10,000 individuals remaining in the wild, this plant is at risk of disappearing forever.

If you’re interested in growing largeleaf phyllostegia, please only obtain plants or seeds from reputable native plant nurseries that use responsibly sourced, legally collected material. Never collect from wild populations – every plant in the wild is precious for the species’ survival.

Growing Largeleaf Phyllostegia Successfully

So, should you grow largeleaf phyllostegia? If you can source it responsibly and you’re committed to Hawaiian native plant conservation, absolutely! Here’s what you need to know:

Ideal Growing Conditions

  • Climate: USDA Hardiness Zones 10-11 (year-round warm temperatures)
  • Light: Partial shade to dappled sunlight – think forest understory conditions
  • Soil: Well-draining soil enriched with organic matter
  • Moisture: Consistent but not waterlogged – it’s classified as facultative upland, meaning it usually prefers non-wetland conditions but can tolerate some moisture

Garden Design and Landscape Role

Largeleaf phyllostegia shines in:

  • Native Hawaiian plant gardens
  • Naturalistic understory plantings
  • Conservation gardens focused on rare species
  • Educational gardens showcasing endemic plants

Its soft, herbaceous nature makes it perfect for layering beneath native trees and shrubs, where it can provide ground-level interest without competing for canopy space.

Planting and Care Tips

Growing this rare beauty requires patience and attention:

  • Plant in well-amended soil with good drainage
  • Provide consistent moisture without waterlogging
  • Mulch around plants to retain soil moisture and suppress weeds
  • Protect from strong winds and intense direct sunlight
  • Be patient – as a conservation species, it may grow slowly as it establishes

Benefits for Wildlife and Pollinators

While specific wildlife benefits aren’t extensively documented, as a native Hawaiian plant in the mint family, largeleaf phyllostegia likely provides nectar for native insects and possibly native birds. Every native plant you grow contributes to the complex web of relationships that support Hawaii’s unique ecosystem.

The Bottom Line

Largeleaf phyllostegia isn’t a plant for every gardener – and that’s exactly as it should be. If you’re passionate about Hawaiian native plant conservation, have the right growing conditions, and can source plants responsibly, growing this species is a meaningful way to contribute to its preservation.

By cultivating largeleaf phyllostegia in your garden, you’re not just growing a plant – you’re becoming a steward of Hawaii’s irreplaceable natural heritage. Just remember: with great botanical beauty comes great responsibility!

Largeleaf 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 macrophylla (Gaudich.) Benth. - largeleaf phyllostegia

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