North America Native Plant

Splitleaf Cyanea

Botanical name: Cyanea grimesiana grimesiana

USDA symbol: CYGRG

Life cycle: perennial

Habit: shrub

Native status: Native to Hawaii  

Splitleaf Cyanea: A Rare Hawaiian Treasure for Your Garden If you’re looking to add a touch of tropical elegance to your garden while supporting conservation efforts, the splitleaf cyanea (Cyanea grimesiana grimesiana) might just be your next horticultural obsession. This stunning Hawaiian native is as rare as it is beautiful, ...

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

Splitleaf Cyanea: A Rare Hawaiian Treasure for Your Garden

If you’re looking to add a touch of tropical elegance to your garden while supporting conservation efforts, the splitleaf cyanea (Cyanea grimesiana grimesiana) might just be your next horticultural obsession. This stunning Hawaiian native is as rare as it is beautiful, making it a true gem for dedicated gardeners in warm climates.

What Makes Splitleaf Cyanea Special?

The splitleaf cyanea is a perennial shrub that brings serious tropical vibes to any landscape. This multi-stemmed woody beauty typically reaches 13 to 16 feet in height, creating an impressive presence in your garden. What really sets it apart are its distinctive large, deeply lobed leaves that give the plant its splitleaf common name, paired with spectacular tall flowering spikes adorned with tubular blooms.

A True Hawaiian Native

This remarkable plant is exclusively native to Hawaii, where it naturally thrives in the islands’ wet forest environments. You won’t find this species growing wild anywhere else in the world, making it a unique addition to gardens in tropical and subtropical regions.

Important Conservation Note

Here’s where things get serious: splitleaf cyanea is listed as Endangered in the United States, with a Global Conservation Status of S1T1. This means it’s incredibly rare and faces significant threats in its native habitat. If you’re considering adding this plant to your garden, you absolutely must source it responsibly from reputable nurseries that propagate plants legally and ethically. Never collect plants from the wild – doing so could further harm already vulnerable populations.

Growing Splitleaf Cyanea Successfully

If you’re fortunate enough to obtain responsibly sourced splitleaf cyanea, here’s what you need to know to help it thrive:

Ideal Growing Conditions

  • Climate zones: USDA zones 10-12 only
  • Light: Shade to partial shade (mimics its native forest habitat)
  • Humidity: High humidity is essential
  • Soil: Well-draining but consistently moist, rich organic matter
  • Protection: Shield from strong winds

Planting and Care Tips

  • Choose a sheltered location with filtered light
  • Maintain consistent moisture without waterlogging
  • Provide regular misting to increase humidity
  • Use organic mulch to retain moisture and suppress weeds
  • Be patient – this plant grows at a moderate pace

Wildlife and Pollinator Benefits

When splitleaf cyanea blooms, it becomes a magnet for native Hawaiian birds, particularly honeycreepers, which have co-evolved with this plant. The tubular flowers are perfectly designed for these specialized pollinators, making your garden a potential conservation sanctuary.

Perfect for Specialized Gardens

This isn’t your average garden plant – splitleaf cyanea is best suited for:

  • Tropical and subtropical shade gardens
  • Conservation-focused landscapes
  • Specimen plantings where its unique form can be appreciated
  • Hawaiian-themed or native plant gardens

The Bottom Line

Growing splitleaf cyanea is both a privilege and a responsibility. While this stunning Hawaiian native can add incredible beauty and ecological value to your garden, its endangered status means it’s not for casual gardeners. If you have the right climate, dedication to proper care, and access to responsibly sourced plants, you’ll be rewarded with a truly exceptional addition to your landscape – and you’ll be supporting the conservation of a remarkable species.

Remember: always verify that any plants you purchase are legally and ethically sourced, and consider this an investment in both your garden’s future and the preservation of Hawaii’s unique botanical heritage.

Splitleaf 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 grimesiana Gaudich. - splitleaf cyanea

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