North America Native Plant

O’ahu Cyanea

Botanical name: Cyanea calycina

USDA symbol: CYCA23

Life cycle: perennial

Habit: shrub

Native status: Native to Hawaii  

Synonyms: Cyanea coronata E. Wimm. (CYCO14)  âš˜  Cyanea lanceolata (Gaudich.) Lammers, Givnish & Sytsma ssp. calycina (Cham.) Lammers, Givnish & Sytsma (CYLAC2)  âš˜  Rollandia bidentata H. St. John (ROBI)  âš˜  Rollandia calycina (Cham.) G. Don (ROCA7)  âš˜  Rollandia calycina (Cham.) G. Don var. kaalae (Wawra) E. Wimm. (ROCAK)  âš˜  Rollandia lanceolata Gaudich. ssp. calycina (Cham.) Lammers (ROLAC)  âš˜  Rollandia lanceolata Gaudich. var. tomentella (Wawra) E. Wimm. (ROLAT)  âš˜  Rollandia waianaeensis H. St. John (ROWA2)   

O’ahu Cyanea: A Rare Hawaiian Treasure Worth Protecting Meet the O’ahu cyanea (Cyanea calycina), one of Hawaii’s most endangered native plants that’s as stunning as it is rare. This remarkable perennial shrub represents both the beauty and fragility of Hawaii’s unique flora, making it a plant that deserves our attention ...

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

O’ahu Cyanea: A Rare Hawaiian Treasure Worth Protecting

Meet the O’ahu cyanea (Cyanea calycina), one of Hawaii’s most endangered native plants that’s as stunning as it is rare. This remarkable perennial shrub represents both the beauty and fragility of Hawaii’s unique flora, making it a plant that deserves our attention and protection.

What Makes O’ahu Cyanea Special

The O’ahu cyanea is a true Hawaiian endemic, meaning it exists nowhere else on Earth except on the island of O’ahu. This perennial shrub typically grows as a multi-stemmed woody plant, usually reaching heights of 13 to 16 feet, though it can sometimes grow taller or develop a single stem depending on environmental conditions.

What really sets this plant apart are its spectacular flowers – distinctive purple tubular blooms that curve dramatically, creating an almost otherworldly appearance. These are complemented by large, lobed leaves that give the entire plant an impressive, tropical presence.

Where Does It Come From?

This rare beauty calls only Hawaii home, specifically the Wai’anae Mountains of O’ahu. It’s part of a remarkable family of Hawaiian lobelioids that evolved in isolation over millions of years.

A Plant in Crisis

Important Conservation Alert: The O’ahu cyanea is critically endangered, with a Global Conservation Status of S1 and listed as Endangered in the United States. This means there are typically only 5 or fewer known occurrences in the wild, with fewer than 1,000 individuals remaining. This plant is teetering on the edge of extinction.

If you’re considering growing this plant, it’s crucial to obtain it only through responsible conservation programs or legitimate botanical institutions. Never collect from wild populations, as this could push the species closer to extinction.

Growing Conditions and Care

The O’ahu cyanea is definitely not a beginner’s plant, but for dedicated native plant enthusiasts involved in conservation efforts, here’s what you need to know:

  • Climate: Thrives in USDA hardiness zones 10-11 (tropical climates only)
  • Light: Prefers partial shade, mimicking its natural forest habitat
  • Moisture: Needs consistent moisture but well-draining soil
  • Humidity: Requires high humidity levels
  • Soil: Well-draining, rich organic soil
  • Protection: Needs shelter from strong winds

Garden Role and Landscape Use

This isn’t a plant for typical residential landscapes. The O’ahu cyanea is best suited for:

  • Specialized native Hawaiian plant collections
  • Botanical gardens with conservation programs
  • Educational institutions focused on Hawaiian flora
  • Dedicated conservation gardeners working with legitimate programs

Its wetland status as Facultative Upland means it usually grows in non-wetland areas but can tolerate some wetland conditions, giving it some flexibility in specialized garden settings.

Ecological Importance

The O’ahu cyanea evolved alongside Hawaii’s native birds, particularly the Hawaiian honeycreepers, many of which are now extinct. This represents a tragic ecological disconnect – a plant losing its natural pollinators, making conservation efforts even more critical.

Should You Grow It?

Here’s the honest truth: most gardeners shouldn’t attempt to grow O’ahu cyanea. This plant requires specialized care, specific growing conditions, and should only be grown as part of legitimate conservation efforts. However, if you’re passionate about Hawaiian native plants and can work with established conservation programs, growing this species can be a meaningful contribution to preventing extinction.

For typical native plant enthusiasts, consider supporting conservation efforts through donations to Hawaiian plant conservation organizations or visiting botanical gardens that maintain these rare species. You can also explore growing other Hawaiian natives that are less critically endangered.

The Bottom Line

The O’ahu cyanea represents both the incredible diversity of Hawaiian flora and the urgent need for plant conservation. While it may not be suitable for most home gardens, understanding and supporting the conservation of species like this helps preserve Hawaii’s unique natural heritage for future generations. Sometimes the best way to grow a plant is to help protect its wild habitat and support the scientists and conservationists working to save it from extinction.

O’ahu 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 calycina (Cham.) Lammers - O'ahu cyanea

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