North America Native Plant

Toothleaf Cyrtandra

Botanical name: Cyrtandra halawensis

USDA symbol: CYHA2

Life cycle: perennial

Habit: shrub

Native status: Native to Hawaii  

Toothleaf Cyrtandra: A Rare Hawaiian Native Worth Protecting If you’re passionate about native Hawaiian plants and conservation gardening, the toothleaf cyrtandra (Cyrtandra halawensis) might just capture your heart. This enchanting little shrub is more than just another pretty face in the garden—it’s a critically important piece of Hawaii’s natural heritage ...

Rare plant alert!

Region: Conservation status by state

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) ⚘

Toothleaf Cyrtandra: A Rare Hawaiian Native Worth Protecting

If you’re passionate about native Hawaiian plants and conservation gardening, the toothleaf cyrtandra (Cyrtandra halawensis) might just capture your heart. This enchanting little shrub is more than just another pretty face in the garden—it’s a critically important piece of Hawaii’s natural heritage that desperately needs our help.

What Makes Toothleaf Cyrtandra Special?

The toothleaf cyrtandra is a charming perennial shrub that typically grows as a multi-stemmed woody plant, usually staying under 13-16 feet tall. What sets this beauty apart are its distinctive serrated leaves (hence the toothleaf name) and delicate tubular flowers that bloom in shades of white to pale pink. It’s like nature’s own little work of art, perfectly adapted to Hawaii’s unique ecosystem.

Where Does It Come From?

This remarkable plant is endemic to Hawaii, meaning you won’t find it growing naturally anywhere else on Earth. Specifically, Cyrtandra halawensis calls the Hawaiian islands home, where it has evolved over thousands of years to thrive in the archipelago’s unique conditions.

The Reality Check: This Plant is in Serious Trouble

Here’s where things get serious, folks. The toothleaf cyrtandra has a Global Conservation Status of S1, which translates to Critically Imperiled. This means there are typically only 5 or fewer known populations, with very few remaining individuals (fewer than 1,000 plants total). We’re talking about a plant that’s teetering on the edge of extinction.

If you’re considering growing this plant, please only source it from reputable native plant nurseries or conservation programs that can guarantee responsibly propagated material. Never collect from wild populations—every single plant in the wild is precious and irreplaceable.

Why Grow Toothleaf Cyrtandra?

Despite—or perhaps because of—its rarity, there are compelling reasons to consider this plant:

  • Conservation impact: By growing responsibly sourced plants, you’re directly supporting conservation efforts
  • Unique beauty: Those serrated leaves and delicate flowers create an understory accent unlike anything else
  • Cultural significance: You’re preserving a piece of authentic Hawaiian flora
  • Pollinator support: The flowers attract native Hawaiian birds and beneficial insects

Growing Conditions: Creating a Hawaiian Paradise

Toothleaf cyrtandra isn’t your typical backyard shrub—it has some specific needs that reflect its native Hawaiian habitat:

  • Climate: USDA hardiness zones 10-12 only (think tropical and subtropical)
  • Light: Prefers shaded conditions—think understory rather than full sun
  • Moisture: Needs consistent humidity and regular watering
  • Soil: Well-draining but moisture-retentive soil rich in organic matter

Perfect Garden Settings

This shrub shines in:

  • Shade gardens where it can serve as an understory accent
  • Native Hawaiian landscape designs
  • Conservation-focused gardens
  • Humid, protected areas with filtered light

Planting and Care Tips

Growing toothleaf cyrtandra successfully requires attention to detail:

  • Location: Choose a spot with bright, indirect light and protection from harsh winds
  • Soil prep: Amend with lots of organic compost to improve drainage while retaining moisture
  • Watering: Keep soil consistently moist but never waterlogged
  • Humidity: Mist regularly or use a humidifier if growing indoors
  • Fertilizing: Use a balanced, slow-release fertilizer sparingly

The Bottom Line

Toothleaf cyrtandra isn’t for everyone—it requires specific tropical conditions and a commitment to conservation-minded gardening. But if you live in the right climate zone and can source plants responsibly, you’ll be rewarded with a truly unique shrub that connects you directly to Hawaii’s irreplaceable natural heritage.

Remember, every plant grown from responsibly sourced material is a small victory in the fight to save this critically imperiled species. Sometimes the most meaningful gardens are the ones that help write conservation success stories, one plant at a time.

Toothleaf Cyrtandra

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

Scrophulariales

Family

Gesneriaceae Rich. & Juss. - Gesneriad family

Genus

Cyrtandra J.R. Forst. & G. Forst. - cyrtandra

Species

Cyrtandra halawensis Rock - toothleaf cyrtandra

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