North America Non-native Plant

Osmoxylon Mariannense

Botanical name: Osmoxylon mariannense

USDA symbol: OSMA

Native status: Not native but doesn't reproduce and persist in the wild

Osmoxylon mariannense: A Critically Endangered Plant Worth Protecting Meet Osmoxylon mariannense, a plant so rare that most gardeners will never encounter it in their lifetime. This mysterious member of the ginseng family (Araliaceae) represents one of nature’s most precious botanical treasures – and one of its most vulnerable. A Plant ...

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

Osmoxylon mariannense: A Critically Endangered Plant Worth Protecting

Meet Osmoxylon mariannense, a plant so rare that most gardeners will never encounter it in their lifetime. This mysterious member of the ginseng family (Araliaceae) represents one of nature’s most precious botanical treasures – and one of its most vulnerable.

A Plant on the Brink

Here’s something that might surprise you: Osmoxylon mariannense holds a Global Conservation Status of S1, meaning it’s critically imperiled. With typically five or fewer known occurrences and fewer than 1,000 remaining individuals in the wild, this plant is officially listed as Endangered. When we talk about rare plants, this one takes the cake – and then some!

Where in the World?

While specific distribution details are closely guarded due to conservation concerns, the species name mariannense suggests a connection to the Mariana Islands region. Like many island endemic species, this plant likely evolved in isolation, making it particularly vulnerable to habitat loss and environmental changes.

Should You Grow Osmoxylon mariannense?

Here’s where we need to have a serious conversation. While the allure of growing something incredibly rare might be tempting, Osmoxylon mariannense isn’t your typical garden center find – and that’s for good reason.

The reality check: This plant is so rare that casual cultivation could actually harm wild populations if plants are collected inappropriately. Additionally, its specific growing requirements are not well-documented, making successful cultivation extremely challenging for home gardeners.

If You’re Serious About Conservation

If you’re genuinely interested in supporting this species, consider these responsible approaches:

  • Support botanical gardens and conservation organizations working with rare Pacific Island flora
  • Only source plants through legitimate conservation programs with proper documentation
  • Partner with research institutions that may be studying the species
  • Focus on creating habitat for other native species in your region instead

The Growing Mystery

Here’s the thing about extremely rare plants – their growing requirements often remain as mysterious as the plants themselves. Without extensive cultivation experience, we simply don’t know the specific conditions Osmoxylon mariannense needs to thrive in a garden setting. This uncertainty, combined with its endangered status, makes it unsuitable for typical home cultivation.

Better Alternatives for Your Garden

Instead of pursuing this endangered species, why not celebrate your local native flora? Every region has its own botanical treasures that are better suited for home gardens and actually need your support. Research native plants in your area – you might discover something equally fascinating that you can grow responsibly while supporting local ecosystems.

The Takeaway

Osmoxylon mariannense serves as a powerful reminder of how fragile our plant diversity can be. Rather than adding it to our wish lists, let’s appreciate it as a symbol of the urgent need for plant conservation. Sometimes the best way to love a plant is to protect it in its natural habitat rather than trying to grow it in our gardens.

The plant world is full of wonders, and while this particular species may be off-limits for cultivation, there are countless other native plants waiting to bring beauty, ecological value, and wonder to your garden. Let’s celebrate those instead while keeping our fingers crossed that future generations will still get to marvel at Osmoxylon mariannense in the wild.

Osmoxylon Mariannense

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

Apiales

Family

Araliaceae Juss. - Ginseng family

Genus

Osmoxylon Miq.

Species

Osmoxylon mariannense (Kaneh.) Fosberg & Sachet

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