North America Native Plant

Maui Island-aster

Botanical name: Hesperomannia arbuscula

USDA symbol: HEAR10

Life cycle: perennial

Habit: shrub

Native status: Native to Hawaii  

Synonyms: Hesperomannia arbuscula Hillebr. ssp. oahuensis (Hillebr.) Carlq. (HEARO)  âš˜  Hesperomannia arbuscula Hillebr. var. pearsallii H. St. John (HEARP)  âš˜  Hesperomannia mauiensis H. St. John (HEMA13)   

Maui Island-Aster: A Rare Hawaiian Treasure Worth Protecting Meet the Maui island-aster (Hesperomannia arbuscula), one of Hawaii’s most endangered native shrubs. This delicate beauty might not be the easiest plant to find at your local nursery, but it represents something truly special in the world of Hawaiian native plants – ...

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

Maui Island-Aster: A Rare Hawaiian Treasure Worth Protecting

Meet the Maui island-aster (Hesperomannia arbuscula), one of Hawaii’s most endangered native shrubs. This delicate beauty might not be the easiest plant to find at your local nursery, but it represents something truly special in the world of Hawaiian native plants – a living piece of the islands’ natural heritage that desperately needs our help.

What Makes This Plant So Special?

The Maui island-aster is a perennial shrub that typically grows as a multi-stemmed woody plant, usually staying under 13-16 feet tall. Its charming daisy-like flowers and narrow leaves give it a delicate, almost ethereal appearance that perfectly captures the unique beauty of Hawaii’s native flora.

But here’s what makes this plant truly remarkable – it’s found nowhere else on Earth except Hawaii. This endemic species is part of the exclusive club of plants that evolved specifically in the Hawaiian Islands, making it an irreplaceable part of the local ecosystem.

A Critical Conservation Story

Important Conservation Alert: Before we talk about growing this beauty, you need to know that Hesperomannia arbuscula is critically endangered. With a Global Conservation Status of S1 (Critically Imperiled) and listed as Endangered, this species typically has only 5 or fewer occurrences and very few remaining individuals in the wild.

This means that while we absolutely encourage supporting this species, any planting should only be done with responsibly sourced material from legitimate conservation programs or certified native plant nurseries. Never collect from wild populations!

Where Does It Call Home?

The Maui island-aster is native to Hawaii and historically grew on both Maui and Oahu. Today, its presence is extremely limited, making every remaining plant precious for conservation efforts.

Garden Role and Landscape Use

If you’re fortunate enough to obtain responsibly sourced plants, the Maui island-aster serves several important roles:

  • Conservation gardens: Perfect for native Hawaiian plant collections focused on preservation
  • Educational landscapes: Tells the story of Hawaii’s unique endemic flora
  • Xerophytic gardens: Suits dry, well-draining landscape designs
  • Native restoration projects: Essential for habitat restoration efforts

Growing Conditions and Care

The Maui island-aster thrives in conditions that mimic its natural habitat:

  • Climate: USDA hardiness zones 10-11 (tropical and subtropical)
  • Soil: Well-draining volcanic soils or similar fast-draining mixes
  • Water: Dry to moderately moist conditions; drought-tolerant once established
  • Sun: Partial shade to full sun, depending on local climate
  • Wind protection: Benefits from protection from strong trade winds

Planting and Care Tips

If you’re working with a conservation program or have access to legitimately sourced plants:

  • Plant in well-amended, fast-draining soil
  • Water regularly during establishment, then reduce frequency
  • Mulch around the base to retain moisture and suppress weeds
  • Avoid over-fertilizing – native Hawaiian plants often prefer lean soils
  • Monitor for pests, particularly invasive insects that can harm native species

Supporting Conservation Without Planting

Can’t find responsibly sourced plants? You can still help:

  • Support local conservation organizations working to protect Hawaiian native plants
  • Choose other native Hawaiian plants that are more readily available
  • Remove invasive plants from your property that compete with natives
  • Educate others about the importance of Hawaii’s endemic species

The Bottom Line

The Maui island-aster represents both the incredible uniqueness and the fragility of Hawaii’s native ecosystems. While this rare beauty isn’t for every garden, it serves as a powerful reminder of what we stand to lose if we don’t actively protect our native plants.

If you’re passionate about native Hawaiian plants and have access to legitimate sources, growing this species can be part of important conservation efforts. Just remember – every plant counts when you’re dealing with a species this rare, so responsible sourcing isn’t just recommended, it’s essential for the species’ survival.

Maui Island-aster

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

Asterales

Family

Asteraceae Bercht. & J. Presl - Aster family

Genus

Hesperomannia A. Gray - island-aster

Species

Hesperomannia arbuscula Hillebr. - Maui island-aster

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