Native Plants

Nioi

Eugenia koolauensis

USDA symbol: EUKO

perennial shrub

Hawaii: native

Meet nioi, one of Hawaii’s most precious and precarious native plants. This unassuming shrub might not be making waves in garden centers, but it’s making headlines in conservation circles – and for good reason. If you’re considering adding this plant to your garden, we need to have a serious conversation ...

Nioi may be listed as rare in your area.
Global Conservation Status

Status: S1 | Critically imperiled: Typically 5 or fewer occurrences or under 1,000 remaining individuals.

United States

Status: Endangered | Endangered. In danger of extinction throughout all or a significant portion of its range.

Nioi (Eugenia koolauensis): Hawaii’s Critically Endangered Native Treasure

Meet nioi, one of Hawaii’s most precious and precarious native plants. This unassuming shrub might not be making waves in garden centers, but it’s making headlines in conservation circles – and for good reason. If you’re considering adding this plant to your garden, we need to have a serious conversation first.

What Makes Nioi Special?

Eugenia koolauensis, commonly known as nioi, is a native Hawaiian shrub that belongs to the myrtle family. This perennial woody plant typically grows as a multi-stemmed shrub, usually reaching heights of 13 to 16 feet, though it can vary depending on environmental conditions. You might also see it referenced by its botanical synonym, Eugenia molokaiana Wilson & Rock.

Where Does Nioi Call Home?

Nioi is endemic to Hawaii, meaning it exists nowhere else on Earth. This remarkable plant has made its home exclusively in the Hawaiian Islands, where it has evolved over thousands of years to thrive in the unique island ecosystem.

  • Species observed
  • No observations

The Critical Conservation Status

Here’s where things get serious: Nioi is critically imperiled with a Global Conservation Status of S1 and is listed as Endangered in the United States. This means there are typically five or fewer occurrences of this plant in the wild, with very few remaining individuals – we’re talking fewer than 1,000 plants total.

What does this mean for you as a gardener? Simply put: you should not attempt to grow this plant in your garden.

Why You Shouldn’t Plant Nioi

While we’re all about celebrating native plants, nioi falls into a special category that requires our protection rather than our cultivation. Here’s why:

  • Extreme rarity: With so few plants remaining in the wild, any removal from natural populations could push the species closer to extinction
  • Conservation priority: Every remaining plant is crucial for the species’ survival and should remain in protected habitats
  • Specialized needs: This plant has evolved for very specific Hawaiian mountain conditions that are nearly impossible to replicate in home gardens
  • Legal considerations: Collecting endangered plants from the wild is illegal and can result in serious penalties

How You Can Help Instead

Just because you can’t grow nioi doesn’t mean you can’t make a difference! Here are meaningful ways to support this endangered beauty:

  • Support local Hawaiian native plant societies and conservation organizations
  • Choose other native Hawaiian plants for your garden that aren’t endangered
  • Participate in habitat restoration projects if you live in Hawaii
  • Spread awareness about the importance of protecting endangered native species

Native Hawaiian Alternatives for Your Garden

If you’re passionate about growing native Hawaiian plants (and you should be!), consider these less imperiled options that can thrive in cultivation:

  • ʻŌhiʻa lehua (Metrosideros polymorpha) – Hawaii’s iconic flowering tree
  • Naupaka (Scaevola taccada) – A hardy coastal shrub
  • ʻĀweoweo (Chenopodium oahuense) – An attractive native herb

The Bigger Picture

Nioi’s story is a reminder of how precious and fragile our native plant heritage can be. While we can’t invite this particular species into our gardens, we can honor it by becoming better stewards of the native plants we can grow, supporting conservation efforts, and making thoughtful choices about the plants we choose to cultivate.

Sometimes the most loving thing we can do for a plant is to admire it from afar and ensure its wild populations have the best chance of survival for future generations to discover and appreciate.

Eugenia koolauensis is also known as...

Often we refer to plants by their common names. When shopping for plants the scientific name is the best way to positively identify the plant species you desire. But some plants have more than one name! While it doesn't happen often, nurseries might display one name while you're searching for another. Eugenia koolauensis is also known as:

Eugenia molokaiana Wilson & | USDA symbol: EUMO2

Why do some plants have more than one name? Over time plant species may be renamed for a few reasons:

  1. Botanists in different regions named the same plant without knowing it had already been classified.
  2. A species was reclassified after scientific advances in, for example, DNA analysis.
  3. Slight variations within a species are sometimes mistakenly identified as entirely new species.

Classification

Group: Dicot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Class: Magnoliopsida - Dicotyledons
Subclass: Rosidae
Order: Myrtales
Family: Myrtaceae Juss. - Myrtle family
Genus: Eugenia L. - stopper

Species: Eugenia koolauensis O. Deg. - nioi

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