North America Native Plant

Smallflower Phyllostegia

Botanical name: Phyllostegia parviflora var. lydgatei

USDA symbol: PHPAL

Life cycle: perennial

Habit: forb

Native status: Native to Hawaii  

Synonyms: Phyllostegia mollis Benth. var. lydgatei Sherff (PHMOL)   

Smallflower Phyllostegia: A Rare Hawaiian Treasure for Conservation Gardeners If you’re passionate about Hawaiian native plants and conservation gardening, you may have heard whispers about the smallflower phyllostegia (Phyllostegia parviflora var. lydgatei). This little-known member of the mint family is one of Hawaii’s botanical gems – but it’s also one ...

Rare plant alert!

Region: Conservation status by state

Status: S1T1: 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) ⚘ Subspecies or variety is 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) ⚘

Smallflower Phyllostegia: A Rare Hawaiian Treasure for Conservation Gardeners

If you’re passionate about Hawaiian native plants and conservation gardening, you may have heard whispers about the smallflower phyllostegia (Phyllostegia parviflora var. lydgatei). This little-known member of the mint family is one of Hawaii’s botanical gems – but it’s also one that needs our help to survive.

What Makes This Plant Special?

The smallflower phyllostegia is a perennial forb that’s endemic to the Hawaiian Islands, meaning it exists nowhere else on Earth. As part of the mint family, it shares that characteristic square stem and aromatic foliage that makes mints so distinctive. But unlike the aggressive spreaders you might know from your herb garden, this Hawaiian native is delicate and refined.

This herbaceous perennial produces small, tubular flowers that range from white to pale purple, creating a subtle but charming display. The blooms may be modest in size – hence the smallflower common name – but they’re perfectly designed to attract Hawaii’s native pollinators and beneficial insects.

Where Does It Grow?

Smallflower phyllostegia is found exclusively in Hawaii, with populations historically documented on Kauai and Oahu. This narrow geographic distribution is part of what makes it so special – and so vulnerable.

A Plant in Need: Understanding Its Rarity

Here’s where things get serious: smallflower phyllostegia has a Global Conservation Status of S1T1, which means it’s critically imperiled. This isn’t just rare – it’s hanging on by a thread. Habitat loss, invasive species, and other human impacts have pushed this native beauty to the brink.

If you’re considering growing this plant, please only source it from reputable conservation nurseries or native plant societies that can guarantee responsibly propagated material. Never collect from wild populations – every plant in the wild is precious for the species’ survival.

Growing Smallflower Phyllostegia: A Labor of Love

This isn’t a plant for casual gardeners, but if you’re committed to Hawaiian conservation and have experience with native plants, it can be incredibly rewarding to grow.

Ideal Growing Conditions

  • Climate: USDA zones 10-11 only (tropical and subtropical climates)
  • Light: Partial shade – it naturally grows as an understory plant
  • Soil: Well-draining, organically rich soil that mimics native forest conditions
  • Water: Consistent moderate moisture, but never waterlogged

Planting and Care Tips

  • Plant in a protected location that mimics its native forest understory habitat
  • Apply organic mulch to retain moisture and suppress weeds
  • Water regularly but ensure good drainage to prevent root rot
  • Protect from strong winds and direct afternoon sun
  • Be patient – this is a slow-growing species that rewards careful attention

Its Role in Your Garden

In the right setting, smallflower phyllostegia makes an excellent addition to native Hawaiian restoration gardens or naturalistic shade gardens. It works beautifully as a ground cover or understory plant, especially when paired with other native Hawaiian species like native ferns or other indigenous forbs.

The plant attracts native Hawaiian pollinators and beneficial insects, making it valuable for supporting local ecosystems. Every garden that includes this species becomes a small conservation sanctuary.

Should You Grow It?

This is a plant for gardeners who are serious about conservation. If you:

  • Live in Hawaii or another suitable tropical climate
  • Have experience with native plant cultivation
  • Can source plants responsibly
  • Want to contribute to conservation efforts

Then smallflower phyllostegia could be a meaningful addition to your garden. Just remember that with great botanical beauty comes great responsibility – you’d be helping preserve one of Hawaii’s rarest native plants for future generations.

For most gardeners outside of Hawaii or those new to native plants, consider starting with more common native species in your area. But if you’re up for the challenge and committed to conservation, this little mint family member offers the chance to be part of something truly special.

Smallflower 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 parviflora (Gaudich.) Benth. - smallflower phyllostegia

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