North America Native Plant

Pilo ‘ula

Botanical name: Melicope cruciata

USDA symbol: MECR5

Life cycle: perennial

Habit: tree

Native status: Native to Hawaii  

Synonyms: Pelea cruciata A. Heller (PECR4)   

Pilo ‘Ula: Hawaii’s Rare Native Treasure Worth Protecting Meet pilo ‘ula (Melicope cruciata), one of Hawaii’s most endangered native trees that deserves a spot in every conservation-minded gardener’s heart. This remarkable species isn’t just another pretty tree – it’s a living piece of Hawaiian natural heritage that’s fighting for survival ...

Rare plant alert!

Region: Conservation status by state

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) ⚘

Pilo ‘Ula: Hawaii’s Rare Native Treasure Worth Protecting

Meet pilo ‘ula (Melicope cruciata), one of Hawaii’s most endangered native trees that deserves a spot in every conservation-minded gardener’s heart. This remarkable species isn’t just another pretty tree – it’s a living piece of Hawaiian natural heritage that’s fighting for survival in the wild.

What Makes Pilo ‘Ula Special?

Pilo ‘ula is a perennial tree native exclusively to the Hawaiian Islands, making it a true endemic treasure. This woody wonder typically grows as a single-stemmed tree reaching heights of 13-16 feet or more, though environmental conditions can sometimes create shorter, multi-stemmed specimens that are equally charming.

The tree produces delicate clusters of small, white to cream-colored flowers that create a subtle but elegant display. Its compound leaves and eventual small capsular fruits add year-round interest to any landscape lucky enough to host this rare beauty.

Where Does It Call Home?

This Hawaiian endemic grows naturally across several islands including Kauai, Oahu, Molokai, and Maui. You’ll find it thriving in Hawaii’s diverse ecosystems, from coastal areas to higher elevation forests.

A Critical Conservation Concern

Here’s the important part: Pilo ‘ula has a Global Conservation Status of S1, meaning it’s critically imperiled. With typically fewer than 5 occurrences or very few remaining individuals (less than 1,000), this tree is hanging on by a thread in the wild.

If you’re considering adding pilo ‘ula to your garden, please only source plants from reputable native plant nurseries or conservation programs that propagate from existing cultivated specimens. Never collect from wild populations – every wild tree is precious for the species’ survival.

Garden Role and Landscape Design

Pilo ‘ula shines as:

  • A stunning specimen tree for native Hawaiian landscapes
  • An important component in habitat restoration projects
  • A conversation starter about Hawaiian conservation
  • A culturally significant addition to ethnobotanical gardens

This tree works beautifully in native Hawaiian gardens, conservation-focused landscapes, and botanical collections where its rarity and cultural importance can be properly appreciated and protected.

Growing Conditions and Care

Pilo ‘ula is surprisingly adaptable, with a wetland status of facultative, meaning it can handle both wetland and non-wetland conditions. Here’s what this resilient tree needs to thrive:

  • Climate: USDA zones 10-12 (tropical to subtropical)
  • Sunlight: Partial shade to full sun
  • Soil: Well-draining soil is essential
  • Water: Regular watering, especially during establishment
  • Protection: Shield from strong winds when young

Planting and Care Tips

When planting your responsibly-sourced pilo ‘ula:

  • Choose a location with good drainage – soggy roots spell trouble
  • Water regularly during the first year while roots establish
  • Mulch around the base to retain moisture and suppress weeds
  • Be patient – like many native trees, pilo ‘ula takes its time to establish
  • Consider companion planting with other native Hawaiian species

Supporting Pollinators and Wildlife

While specific wildlife benefits aren’t well-documented, pilo ‘ula’s flowers likely attract native Hawaiian insects and other pollinators. By growing this tree, you’re not just creating habitat – you’re helping maintain the genetic diversity crucial for this species’ survival.

The Bottom Line

Should you plant pilo ‘ula? If you can source it responsibly and have the right growing conditions, absolutely! You’ll be participating in conservation efforts while enjoying a unique piece of Hawaiian natural heritage. Just remember – with great beauty comes great responsibility. This isn’t just any tree; it’s a critically endangered species that needs our help to survive.

By choosing pilo ‘ula for your garden, you’re not just planting a tree – you’re planting hope for Hawaii’s botanical future.

Pilo ‘ula

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 cruciata (A. Heller) T.G. Hartley & B.C. Stone - pilo 'ula

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