North America Native Plant

Oahu Rollandia

Botanical name: Cyanea humboldtiana

USDA symbol: CYHU2

Life cycle: perennial

Habit: shrub

Native status: Native to Hawaii  

Synonyms: Rollandia humboldtiana Gaudich. (ROHU2)   

Oahu Rollandia: A Critically Endangered Hawaiian Native Worth Protecting If you’re passionate about native Hawaiian plants and conservation, you’ve probably heard whispers about the Oahu rollandia (Cyanea humboldtiana). This remarkable shrub represents both the incredible diversity of Hawaii’s native flora and the urgent conservation challenges facing island ecosystems today. What ...

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

Oahu Rollandia: A Critically Endangered Hawaiian Native Worth Protecting

If you’re passionate about native Hawaiian plants and conservation, you’ve probably heard whispers about the Oahu rollandia (Cyanea humboldtiana). This remarkable shrub represents both the incredible diversity of Hawaii’s native flora and the urgent conservation challenges facing island ecosystems today.

What Makes Oahu Rollandia Special?

The Oahu rollandia is a perennial shrub that belongs to the bellflower family, and it’s as rare as it is beautiful. This multi-stemmed woody plant typically grows to about 13-16 feet tall, though it can sometimes reach greater heights or remain single-stemmed depending on environmental conditions. What makes this plant truly special isn’t just its striking appearance, but its incredible rarity and cultural significance to Hawaii.

A Plant in Crisis: Understanding Its Rarity

Important Conservation Alert: Before we dive into growing tips, it’s crucial to understand that Oahu rollandia is critically imperiled. With a Global Conservation Status of S1 and listed as Endangered in the United States, this plant typically has only 5 or fewer occurrences in the wild with very few remaining individuals (fewer than 1,000). This means that any cultivation efforts must use only responsibly sourced, legally obtained plant material.

Where Does Oahu Rollandia Call Home?

This endemic treasure is found exclusively in Hawaii, specifically on the island of Oahu. As a native Hawaiian species, it has evolved over thousands of years to thrive in the unique conditions of its island home. The plant has adapted to Hawaii’s tropical climate and plays an important role in the native ecosystem.

Garden Potential and Landscape Role

While most home gardeners won’t have access to Oahu rollandia due to its rarity, it serves important roles in specialized settings:

  • Native Hawaiian restoration projects
  • Botanical gardens and conservation collections
  • Educational and research facilities
  • Specialized native plant gardens with proper permits

The plant’s tubular flowers, typical of the bellflower family, likely provide nectar for native Hawaiian pollinators, making it an important piece of the island’s ecological puzzle.

Growing Conditions and Care

If you’re working with a legitimate conservation program or botanical institution, here’s what Oahu rollandia needs to thrive:

Climate Requirements: This tropical native thrives in USDA hardiness zones 10-11, requiring the warm, humid conditions found in Hawaii year-round.

Moisture Needs: The plant has a facultative wetland status in Hawaii, meaning it can grow in both wetland and non-wetland conditions. This suggests it’s adaptable to varying moisture levels but likely prefers consistent hydration.

Growing Environment: As a native Hawaiian shrub, it likely prefers:

  • Partial shade to filtered sunlight
  • Well-draining but moisture-retentive soil
  • Protection from strong winds
  • Tropical humidity levels

The Conservation Garden Approach

Rather than attempting to grow this endangered species, consider these alternatives for your native Hawaiian garden:

  • Support conservation organizations working to protect Oahu rollandia
  • Choose other native Hawaiian plants that aren’t critically endangered
  • Create habitat that could potentially support reintroduced populations in the future
  • Visit botanical gardens where you can appreciate this species in person

Why This Matters for Every Gardener

Even if you’ll never grow an Oahu rollandia yourself, this plant’s story highlights the importance of native plant conservation. Every endangered species represents thousands of years of evolution and irreplaceable genetic diversity. By choosing native plants in our own gardens and supporting conservation efforts, we contribute to preserving botanical treasures like the Oahu rollandia for future generations.

The next time you’re planning your garden, remember the Oahu rollandia and let its story inspire you to make choices that support native plant conservation in your own region. After all, every garden can be a small act of conservation – we just need to plant with purpose.

Oahu Rollandia

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 humboldtiana (Gaudich.) Lammers, Givnish & Sytsma - Oahu rollandia

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