North America Native Plant

Kunana Pepperwort

Botanical name: Lepidium bidentatum var. owaihiense

USDA symbol: LEBIO

Life cycle: annual

Habit: subshrub

Native status: Native to Hawaii âš˜ Native to Pacific Basin excluding Hawaii  

Synonyms: Lepidium owaihiense Cham. & Schltdl. (LEOW)   

Kunana Pepperwort: A Rare Pacific Island Native Worth Knowing Meet the Kunana pepperwort (Lepidium bidentatum var. owaihiense), a little-known native plant that calls the Pacific islands home. Also known by its Hawaiian name ‘anaunau, this modest member of the mustard family represents an important piece of Pacific island biodiversity that ...

Rare plant alert!

Region: Conservation status by state

Status: S5T2: Status is uncertain but is somewhere between the following rankings: Subspecies or variety is imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘ Secure: At very low or no risk of extinction in the jurisdiction due to a very extensive range, abundant populations or occurrences, with little to no concern from declines or threats. ⚘

Kunana Pepperwort: A Rare Pacific Island Native Worth Knowing

Meet the Kunana pepperwort (Lepidium bidentatum var. owaihiense), a little-known native plant that calls the Pacific islands home. Also known by its Hawaiian name ‘anaunau, this modest member of the mustard family represents an important piece of Pacific island biodiversity that deserves our attention and respect.

What Makes Kunana Pepperwort Special?

This unassuming plant belongs to the Lepidium genus, commonly known as pepperweeds or peppercresses. The Kunana pepperwort is a forb or herb – essentially a soft-stemmed plant without the woody tissue you’d find in shrubs or trees. It can be either annual or perennial, adapting its life cycle to the conditions of its island home.

What truly sets this plant apart is its rarity. With a Global Conservation Status of S5T2, the Kunana pepperwort is considered a species of conservation concern. This makes it a plant that gardeners and conservationists should know about, even if it’s not commonly available in the nursery trade.

Where Does Kunana Pepperwort Call Home?

This Pacific island native has a unique distribution pattern. You’ll find it growing naturally in Hawaii, Guam, and various U.S. Minor Outlying Islands throughout the Pacific Basin. Its presence across these scattered island locations tells a fascinating story of Pacific plant migration and evolution.

Should You Grow Kunana Pepperwort?

Here’s where things get interesting – and a bit challenging. While the Kunana pepperwort is a legitimate native plant worthy of conservation, there’s currently very little information available about how to successfully cultivate it in home gardens. This isn’t necessarily a bad thing; sometimes our rarest plants are rare for good reason and are best left to professional conservation efforts.

Important consideration for gardeners: If you live in Hawaii or other Pacific islands where this plant is native, and you happen to encounter seeds or plants through legitimate conservation channels, growing it could contribute to local biodiversity. However, due to its rarity status, any planting should only be done with responsibly sourced material from established conservation programs.

The Conservation Connection

Rather than focusing on cultivation tips (which simply aren’t available for this species), let’s talk about why plants like the Kunana pepperwort matter. Island endemic plants like this one often play specialized ecological roles that we’re still discovering. They’ve evolved unique adaptations to their specific environments and represent millions of years of evolutionary history.

Even if you can’t grow this particular plant, knowing about species like the Kunana pepperwort helps us appreciate the incredible diversity of Pacific island flora and the importance of conservation efforts.

What Can Gardeners Do Instead?

If you’re passionate about growing Pacific island natives, consider focusing on more common native species that are readily available and well-documented for cultivation. Many botanical gardens and native plant societies in Hawaii and other Pacific locations can guide you toward native plants that are both appropriate for home gardens and beneficial to local ecosystems.

Supporting conservation organizations that work to protect rare species like the Kunana pepperwort is another meaningful way to contribute to Pacific island biodiversity.

The Bigger Picture

The Kunana pepperwort reminds us that not every plant needs to be in our gardens to be important. Sometimes, the most valuable thing we can do is simply know these species exist, respect their rarity, and support the conservation efforts working to protect them in their natural habitats.

While you probably won’t be adding Kunana pepperwort to your garden anytime soon, learning about rare natives like this one deepens our connection to the natural world and reminds us of the incredible plant diversity that exists beyond our garden gates.

Kunana Pepperwort

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Dilleniidae

Order

Capparales

Family

Brassicaceae Burnett - Mustard family

Genus

Lepidium L. - pepperweed

Species

Lepidium bidentatum Morton - Kunana pepperwort

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