North America Native Plant

Leechleaf Cyanea

Botanical name: Cyanea undulata

USDA symbol: CYUN5

Life cycle: perennial

Habit: shrub

Native status: Native to Hawaii  

Leechleaf Cyanea: A Rare Hawaiian Treasure Worth Protecting If you’re passionate about Hawaiian native plants and conservation, the leechleaf cyanea (Cyanea undulata) might just capture your heart. This extraordinary perennial shrub represents both the beauty and fragility of Hawaii’s unique ecosystem, but growing it comes with serious responsibilities that every ...

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

Leechleaf Cyanea: A Rare Hawaiian Treasure Worth Protecting

If you’re passionate about Hawaiian native plants and conservation, the leechleaf cyanea (Cyanea undulata) might just capture your heart. This extraordinary perennial shrub represents both the beauty and fragility of Hawaii’s unique ecosystem, but growing it comes with serious responsibilities that every gardener should understand.

What Makes Leechleaf Cyanea Special?

Leechleaf cyanea is a member of the bellflower family that’s found nowhere else on Earth except the Hawaiian Islands. This multi-stemmed woody perennial typically grows 13 to 16 feet tall, though it can sometimes reach greater heights under ideal conditions. What sets it apart are its distinctive palmately lobed leaves and striking tubular flowers that evolved specifically to attract native Hawaiian birds.

A Plant on the Brink

Important Conservation Alert: Before considering this plant for your garden, you need to know that leechleaf cyanea is critically endangered. With a Global Conservation Status of S1 (Critically Imperiled) and listed as Endangered under federal protection, this species has fewer than 1,000 individuals remaining in the wild, possibly as few as five natural populations.

If you’re interested in growing this rare beauty, you must only source it through legitimate conservation programs or botanical institutions that work with responsibly propagated material. Never collect from the wild – doing so could contribute to its extinction.

Where Does It Naturally Grow?

Leechleaf cyanea is endemic to Hawaii, where it once thrived in the islands’ cool, moist forest ecosystems. These specialized environments provided the perfect combination of filtered sunlight, consistent moisture, and high humidity that this species requires.

Is This Plant Right for Your Garden?

Growing leechleaf cyanea is definitely not for beginners – it’s a plant that demands very specific conditions and dedicated care. Here’s what you need to consider:

Ideal Growing Conditions

  • Climate: USDA hardiness zones 10-11, specifically Hawaiian tropical conditions
  • Light: Filtered sunlight or partial shade, mimicking forest understory conditions
  • Moisture: Consistently moist but well-draining soil with high ambient humidity
  • Temperature: Cool, stable temperatures typical of Hawaiian mountain forests

Garden Design Role

If you can provide the right conditions, leechleaf cyanea serves as an exceptional specimen plant for:

  • Hawaiian native plant gardens
  • Conservation-focused botanical collections
  • Educational landscapes highlighting endangered species
  • Specialized tropical gardens with controlled microclimates

Planting and Care Tips

Successfully growing leechleaf cyanea requires recreating its natural forest habitat:

  • Plant in areas with morning sun and afternoon shade
  • Ensure excellent drainage while maintaining consistent soil moisture
  • Provide wind protection to prevent damage to stems and leaves
  • Maintain high humidity through misting or placement near water features
  • Use organic mulch to keep roots cool and moist

Supporting Conservation Through Gardening

The tubular flowers of leechleaf cyanea evolved to be pollinated by native Hawaiian honeycreepers – birds that are also critically endangered. By growing this plant (when responsibly sourced), you’re not just adding beauty to your garden; you’re participating in crucial conservation efforts to preserve Hawaii’s unique evolutionary heritage.

The Bottom Line

Leechleaf cyanea isn’t a casual gardening choice – it’s a commitment to conservation. If you have the right growing conditions, access to responsibly sourced plants, and dedication to providing specialized care, this rare Hawaiian endemic can be an incredibly rewarding addition to your garden. Just remember that with great botanical beauty comes great responsibility to help protect one of Hawaii’s most endangered plant species.

Before pursuing this plant, consider connecting with local botanical gardens, native plant societies, or conservation organizations in Hawaii who might have propagation programs or can guide you toward ethical sources.

Leechleaf Cyanea

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

Campanulales

Family

Campanulaceae Juss. - Bellflower family

Genus

Cyanea Gaudich. - cyanea

Species

Cyanea undulata Forbes - leechleaf cyanea

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