North America Native Plant

Smallflower Phyllostegia

Botanical name: Phyllostegia parviflora var. glabriuscula

USDA symbol: PHPAG

Life cycle: perennial

Habit: forb

Native status: Native to Hawaii  

Smallflower Phyllostegia: A Rare Hawaiian Treasure Worth Protecting Meet smallflower phyllostegia (Phyllostegia parviflora var. glabriuscula), one of Hawaii’s most elusive native plants. If you’ve never heard of this little gem, you’re not alone – this perennial herb is so rare that it’s earned a critically imperiled conservation status, making it ...

Rare plant alert!

Region: Conservation status by state

Status: S1TH: 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) ⚘

Smallflower Phyllostegia: A Rare Hawaiian Treasure Worth Protecting

Meet smallflower phyllostegia (Phyllostegia parviflora var. glabriuscula), one of Hawaii’s most elusive native plants. If you’ve never heard of this little gem, you’re not alone – this perennial herb is so rare that it’s earned a critically imperiled conservation status, making it more of a conservation priority than a common garden choice.

A True Hawaiian Native

Smallflower phyllostegia is exclusively native to Hawaii, making it a genuine island endemic. This perennial forb belongs to a group of plants that lack woody stems above ground but can live for multiple years, storing their energy in underground parts that help them survive and regrow season after season.

Currently, this rare variety is found only in Hawaii, where it clings to existence in increasingly limited locations.

Why This Plant Matters (And Why You Probably Can’t Grow It)

Here’s where things get serious: smallflower phyllostegia has a Global Conservation Status of S1TH, which means it’s critically imperiled. In plain English? This plant is hanging on by a thread in the wild, and every individual matters for the species’ survival.

Conservation Alert: Due to its extremely rare status, we strongly recommend against attempting to grow this plant unless you have access to ethically and responsibly sourced material through legitimate conservation programs or botanical institutions.

What We Know About Growing Conditions

Unfortunately, detailed information about smallflower phyllostegia’s specific growing requirements remains largely undocumented in horticultural literature. As a Hawaiian endemic forb, it likely evolved under very specific environmental conditions that would be challenging to replicate in typical garden settings.

What we can tell you:

  • It’s a perennial forb (non-woody herbaceous plant)
  • It’s adapted to Hawaiian environmental conditions
  • Its rarity suggests it has very specific habitat requirements

Supporting Hawaiian Native Plant Conservation

Instead of trying to grow this rare species, consider these ways to support Hawaiian native plant conservation:

  • Support local Hawaiian botanical gardens and conservation organizations
  • Choose other Hawaiian native plants that are more readily available and less threatened
  • Learn about and advocate for habitat protection in Hawaii
  • Consider donating to organizations working on Hawaiian plant conservation

The Bigger Picture

Smallflower phyllostegia represents the delicate balance of Hawaiian ecosystems and the ongoing challenges facing island plant communities. While we can’t recommend adding this rare beauty to your garden, we can appreciate its importance to Hawaii’s natural heritage and support conservation efforts that help ensure species like this one survive for future generations.

Sometimes the best way to love a plant is to protect it in its native habitat rather than trying to bring it home with us. Smallflower phyllostegia is definitely one of those special plants that deserves our respect and protection from afar.

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