North America Native Plant

Palau Cleistanthus

Botanical name: Cleistanthus insularis

USDA symbol: CLIN8

Life cycle: perennial

Habit: shrub

Native status: Native to Pacific Basin excluding Hawaii  

Palau Cleistanthus: A Rare Pacific Shrub Worth Knowing About Meet the Palau cleistanthus (Cleistanthus insularis), a little-known shrub that calls some of the most remote islands in the Pacific home. While you probably won’t find this plant at your local nursery, it’s worth understanding what makes this species special – ...

Palau Cleistanthus: A Rare Pacific Shrub Worth Knowing About

Meet the Palau cleistanthus (Cleistanthus insularis), a little-known shrub that calls some of the most remote islands in the Pacific home. While you probably won’t find this plant at your local nursery, it’s worth understanding what makes this species special – and why it might be best admired from afar.

Where in the World?

The Palau cleistanthus is native to a very small corner of our planet, specifically found in Guam and Palau in the Pacific Basin. This extremely limited geographic range makes it quite the botanical rarity. When a plant’s entire world consists of just a couple of island locations, you know you’re dealing with something special.

What Does It Look Like?

This perennial shrub typically grows as a multi-stemmed woody plant, usually staying under 13 to 16 feet tall. Like most shrubs, it tends to have several stems growing from or near ground level, giving it that classic bushy appearance. However, depending on its growing conditions, it might surprise you by growing taller or even developing a single main stem.

The Challenge of Growing Palau Cleistanthus

Here’s where things get tricky for us gardening enthusiasts. Despite its intriguing nature, there’s virtually no information available about how to successfully cultivate Cleistanthus insularis. We don’t know:

  • What soil conditions it prefers
  • How much water it needs
  • What USDA hardiness zones it can tolerate
  • Whether it attracts pollinators or benefits wildlife
  • How to propagate it successfully

A Word of Caution

Even if you could somehow get your hands on this plant, there are some important ethical considerations. Given its extremely limited natural range, any Palau cleistanthus should only come from responsibly sourced, legally obtained plant material. The rarity of this species means that wild collection could potentially harm already vulnerable populations.

Better Alternatives for Your Garden

Since growing Palau cleistanthus is both impractical and potentially problematic, why not consider some native shrubs that are better suited to cultivation? Depending on your location, you might explore:

  • Local native shrubs that provide similar structure and form
  • Well-established native species with known growing requirements
  • Plants that offer proven benefits to local wildlife and pollinators

The Bigger Picture

While we might not be able to grow Palau cleistanthus in our backyards, learning about rare species like this one reminds us of the incredible diversity of plant life on our planet. These island endemic plants face unique challenges from habitat loss, climate change, and human development. By choosing to grow native plants in our own regions, we’re supporting local ecosystems and doing our part to preserve botanical diversity closer to home.

Sometimes the most responsible way to appreciate a rare plant is simply to know it exists and to support conservation efforts that help protect its natural habitat. The Palau cleistanthus may remain a mystery to gardeners, but it serves as a beautiful reminder of nature’s endless capacity to surprise us in the most unexpected places.

Palau Cleistanthus

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

Euphorbiales

Family

Euphorbiaceae Juss. - Spurge family

Genus

Cleistanthus Hook. f. ex Planch.

Species

Cleistanthus insularis Kaneh. - Palau cleistanthus

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