North America Native Plant

Fourangle Melicope

Botanical name: Melicope quadrangularis

USDA symbol: MEQU3

Life cycle: perennial

Habit: shrub

Native status: Native to Hawaii  

Synonyms: Pelea quadrangularis H. St. John & Hume (PEQU3)   

Fourangle Melicope: A Critically Endangered Hawaiian Native Worth Protecting Meet the fourangle melicope (Melicope quadrangularis), a rare Hawaiian shrub that’s fighting for survival in the wild but deserves a spotlight in conservation gardening. This perennial woody plant might not be on every gardener’s wish list, but its story is both ...

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

Fourangle Melicope: A Critically Endangered Hawaiian Native Worth Protecting

Meet the fourangle melicope (Melicope quadrangularis), a rare Hawaiian shrub that’s fighting for survival in the wild but deserves a spotlight in conservation gardening. This perennial woody plant might not be on every gardener’s wish list, but its story is both fascinating and heartbreaking—and there’s an important role gardeners can play in its future.

What Makes This Plant Special?

The fourangle melicope gets its name from its distinctive four-angled stems, a quirky botanical feature that sets it apart from its relatives. This native Hawaiian shrub typically grows as a multi-stemmed plant reaching up to 13-16 feet tall, though it usually stays more compact in garden settings. Its glossy green leaves and clusters of small, cream-colored flowers give it a understated elegance that fits perfectly in native Hawaiian landscapes.

A Plant in Crisis

Important Conservation Alert: Before we dive into growing tips, you need to know that fourangle melicope is critically imperiled. With a Global Conservation Status of S1 and listed as Endangered in the United States, this plant is hanging on by a thread in the wild. Typically, there are only 5 or fewer known occurrences with very few remaining individuals (less than 1,000 total).

If you’re considering adding this plant to your garden, it’s crucial that you only source it through legitimate conservation programs or specialized native plant nurseries that propagate from responsibly collected seeds or cuttings.

Where It Calls Home

This endemic Hawaiian species is found naturally only in Hawaii, specifically on the islands of Oahu and Molokai. In the wild, it thrives in mesic to wet forests where it enjoys the filtered light and consistent moisture of Hawaii’s tropical climate.

Growing Fourangle Melicope

Climate Requirements

Fourangle melicope is suited for USDA hardiness zones 10-11, which means it needs tropical conditions to thrive. If you live outside Hawaii, you’ll need a greenhouse or indoor growing setup to provide the warm, humid environment it craves.

Ideal Growing Conditions

  • Light: Partial shade to filtered sunlight (mimicking its forest understory habitat)
  • Soil: Well-draining but consistently moist soil
  • Water: Regular watering to maintain moisture (it has a facultative wetland status, meaning it can handle both wet and moderately dry conditions)
  • Humidity: High humidity levels typical of Hawaiian forests
  • Protection: Shelter from strong winds

Garden Role and Design Uses

In the right setting, fourangle melicope serves as an excellent specimen plant for:

  • Native Hawaiian plant gardens
  • Conservation collections
  • Educational landscapes showcasing endangered species
  • Understory plantings in tropical forest gardens

Care and Maintenance

Once established, fourangle melicope requires consistent care to thrive:

  • Maintain consistent soil moisture without waterlogging
  • Provide protection from harsh direct sunlight
  • Shield from strong winds that can damage its delicate structure
  • Monitor for any signs of stress, as rare plants can be more sensitive than common varieties

Supporting Pollinator Communities

While specific pollinator data for fourangle melicope is limited, its small clustered flowers likely attract native Hawaiian insects and other small pollinators. By growing this plant, you’re potentially providing habitat for the specialized pollinators that co-evolved with Hawaii’s native flora.

The Bottom Line

Fourangle melicope isn’t a plant for every gardener, but it’s a species that deserves our attention and protection. If you’re passionate about Hawaiian native plants and conservation gardening, and you can source this plant responsibly, it could be a meaningful addition to your collection. Just remember—with great rarity comes great responsibility. Every plant grown in cultivation could represent a genetic lifeline for this endangered species.

Consider also supporting conservation organizations working to protect Hawaiian native plants in their natural habitats. Sometimes the best way to help a rare plant is to ensure its wild populations have the protection and habitat they need to recover.

Fourangle Melicope

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Rosidae

Order

Sapindales

Family

Rutaceae Juss. - Rue family

Genus

Melicope (J.R. Forst. & G. Forst.) T.G. Hartley & B.C. Stone - melicope

Species

Melicope quadrangularis (H. St. John & Hume) T.G. Hartley & B.C. Stone - fourangle melicope

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