North America Native Plant

St. John’s Melicope

Botanical name: Melicope saintjohnii

USDA symbol: MESA4

Life cycle: perennial

Habit: tree

Native status: Native to Hawaii  

Synonyms: Pelea elongata (Hillebr.) H. St. John (PEEL3)  âš˜  Pelea saint-johnii Hume (PESA10)  âš˜  Pelea saint-johnii Hume var. elongata (Hillebr.) B.C. Stone (PESAE)   

St. John’s Melicope: A Rare Hawaiian Treasure Worth Protecting Meet St. John’s melicope (Melicope saintjohnii), one of Hawaii’s most precious and endangered native trees. This remarkable species represents both the beauty and fragility of Hawaii’s unique ecosystem, making it a plant that deserves our respect, protection, and careful consideration. A ...

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

St. John’s Melicope: A Rare Hawaiian Treasure Worth Protecting

Meet St. John’s melicope (Melicope saintjohnii), one of Hawaii’s most precious and endangered native trees. This remarkable species represents both the beauty and fragility of Hawaii’s unique ecosystem, making it a plant that deserves our respect, protection, and careful consideration.

A Tree on the Brink

Before we dive into growing this beautiful native, there’s something crucial you need to know: St. John’s melicope is critically endangered. With a Global Conservation Status of S1 and listed as Endangered in the United States, this tree is hanging on by a thread with typically fewer than 5 occurrences and less than 1,000 remaining individuals in the wild.

Important: If you’re considering adding this species to your garden, please ensure you source it only from reputable native plant nurseries or conservation programs that use responsibly collected seeds or ethically propagated material. Never collect from wild populations.

Where This Hawaiian Native Calls Home

St. John’s melicope is endemic to Hawaii, meaning it exists nowhere else on Earth. This perennial tree species has evolved specifically within Hawaii’s unique island ecosystem, making it a true local treasure. You’ll find it naturally occurring only in the Hawaiian Islands, where it has adapted to the tropical climate and specific growing conditions.

What Makes This Tree Special

As a member of the citrus family (Rutaceae), St. John’s melicope grows as a small to medium-sized tree, typically reaching heights greater than 13-16 feet under ideal conditions. Like other trees, it features a single trunk, though environmental pressures can sometimes result in multi-stemmed growth forms or shorter stature.

The tree produces small, delicate flowers that may not be showstoppers from a distance, but up close, they reveal an understated elegance that’s quintessentially Hawaiian. The compound leaves create a lovely texture in the landscape, offering year-round greenery in this perennial species.

Growing St. John’s Melicope Responsibly

If you’re fortunate enough to obtain this rare species through legitimate conservation efforts, here’s what you need to know about growing it successfully:

Climate Requirements

This tropical native thrives in USDA hardiness zones 10-12, making it suitable only for the warmest parts of the United States, primarily Hawaii and southern Florida.

Ideal Growing Conditions

  • Prefers moist, well-draining soils
  • Grows best in partial shade to full sun
  • Needs protection from strong winds
  • Requires consistent moisture without waterlogging
  • Benefits from organic-rich soil similar to its native forest habitat

Planting and Care Tips

  • Plant in a location protected from harsh winds
  • Maintain consistent soil moisture, especially during establishment
  • Mulch around the base to retain moisture and suppress weeds
  • Avoid disturbing the root system once established
  • Consider companion planting with other native Hawaiian species

Conservation Impact in Your Garden

Growing St. John’s melicope isn’t just about adding a unique tree to your landscape—it’s about participating in conservation efforts. When grown from responsibly sourced material, your tree becomes part of a larger effort to preserve this species for future generations.

This tree works beautifully in:

  • Conservation gardens focused on Hawaiian natives
  • Educational landscapes that tell the story of island evolution
  • Native plant gardens that support local ecosystems
  • Restoration projects aimed at preserving Hawaiian biodiversity

Supporting Pollinators and Wildlife

While specific wildlife benefits for this rare species aren’t well-documented, native Hawaiian trees like St. John’s melicope historically played important roles in supporting endemic insects and other native wildlife. By growing this tree, you’re potentially providing habitat and resources for Hawaii’s struggling native ecosystem.

The Bottom Line

St. John’s melicope represents both an opportunity and a responsibility. While most gardeners won’t have access to this critically endangered species, those who do through legitimate conservation channels have the chance to be part of something bigger than their garden—they become guardians of Hawaii’s natural heritage.

If you’re passionate about native Hawaiian plants but can’t access this rare species, consider supporting conservation efforts or choosing other native Hawaiian plants that are more readily available and less endangered. Every native plant in our gardens is a step toward preserving the unique character of Hawaii’s incredible ecosystems.

Remember: with great rarity comes great responsibility. If you’re lucky enough to grow St. John’s melicope, you’re not just a gardener—you’re a conservationist.

St. John’s 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 saint-johnii (Hume) T.G. Hartley & B.C. Stone - St. John's melicope

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