North America Native Plant

Carlson’s Cyanea

Botanical name: Cyanea hamatiflora carlsonii

USDA symbol: CYHAC

Life cycle: perennial

Habit: tree

Native status: Native to Hawaii  

Synonyms: Cyanea carlsonii Rock (CYCA14)   

Carlson’s Cyanea: A Critically Endangered Hawaiian Beauty You Can’t (and Shouldn’t) Grow Meet Carlson’s cyanea (Cyanea hamatiflora carlsonii), one of Hawaii’s most endangered native plants. While this stunning member of the bellflower family might catch your eye with its exotic appeal, this is one plant that belongs in conservation programs, ...

Rare plant alert!

Region: United States

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) ⚘ Endangered: In danger of extinction throughout all or a significant portion of its range. ⚘

Region: United States

Carlson’s Cyanea: A Critically Endangered Hawaiian Beauty You Can’t (and Shouldn’t) Grow

Meet Carlson’s cyanea (Cyanea hamatiflora carlsonii), one of Hawaii’s most endangered native plants. While this stunning member of the bellflower family might catch your eye with its exotic appeal, this is one plant that belongs in conservation programs, not in your garden.

What Makes Carlson’s Cyanea Special?

Also known by its synonym Cyanea carlsonii Rock, this perennial tree is truly a sight to behold. Growing as a single-stemmed woody plant that can reach heights of 13-16 feet or more, Carlson’s cyanea features large, palm-like leaves and distinctive curved, tubular flowers in shades of pink to purple. These unique blooms aren’t just pretty – they’re specially adapted to attract native Hawaiian bird pollinators.

Where Does It Come From?

Carlson’s cyanea is endemic to Hawaii, meaning it exists nowhere else on Earth naturally. This native Hawaiian species once thrived in the islands’ wet forest ecosystems, but today its distribution is severely limited.

Why You Shouldn’t Plant This Beauty

Here’s the sobering reality: Carlson’s cyanea has a Global Conservation Status of S1T1 and is listed as Endangered in the United States. This means it’s critically imperiled and at extremely high risk of extinction. With so few individuals remaining in the wild, every plant matters tremendously to the species’ survival.

Even if you could somehow obtain seeds or cuttings (which you shouldn’t), this tropical tree is incredibly challenging to grow. It requires:

  • USDA hardiness zones 10-11 only
  • Extremely high humidity levels
  • Filtered light conditions that mimic its native forest habitat
  • Specialized soil conditions
  • Expert-level horticultural knowledge

Supporting Conservation Instead

Rather than attempting to grow this endangered species, consider supporting Hawaiian plant conservation efforts. Many botanical gardens and conservation organizations work tirelessly to protect and propagate rare Hawaiian natives like Carlson’s cyanea through responsible, scientific methods.

Garden-Friendly Alternatives

If you’re drawn to the exotic beauty of Hawaiian natives but live in a suitable tropical climate, consider these more garden-appropriate alternatives:

  • Other non-endangered Cyanea species (if available through reputable native plant sources)
  • Native Hawaiian hibiscus varieties
  • Bird of paradise plants
  • Native tropical gingers

The Bigger Picture

Carlson’s cyanea serves as a powerful reminder of why native plant conservation matters. This remarkable tree, with its specialized relationships with native pollinators and its role in Hawaii’s unique ecosystems, represents millions of years of evolution that we simply cannot afford to lose.

While we can’t invite this particular beauty into our gardens, we can appreciate its importance and support the dedicated scientists working to ensure future generations will still be able to marvel at Carlson’s cyanea in its native Hawaiian forests.

Carlson’s 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 hamatiflora Rock - wetforest cyanea

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