Ausu

Ausu (Myrcia paganii): Puerto Rico’s Critically Endangered Hidden Gem

Meet the ausu, a plant so rare that most gardeners will never encounter it—and frankly, that’s probably for the best. This critically endangered shrub from Puerto Rico represents one of nature’s most precious and vulnerable treasures, making it a species we should admire from afar rather than attempt to cultivate in our home gardens.

What Makes Ausu Special?

Ausu (Myrcia paganii) is a perennial shrub native exclusively to Puerto Rico. Like other members of the Myrtaceae family, this multi-stemmed woody plant typically grows to less than 13-16 feet in height, with several stems arising from near the ground. What makes this plant truly remarkable isn’t just its botanical characteristics—it’s how incredibly rare it has become.

A Conservation Crisis in Progress

Here’s where things get serious: ausu has earned a Global Conservation Status of S1, which translates to Critically Imperiled. In plain English, this means the species is hanging on by a thread, with typically five or fewer known occurrences and very few remaining individuals (fewer than 1,000 plants total). In the United States, it’s classified as Endangered, putting it in the same category as some of our most at-risk wildlife.

Where Does Ausu Call Home?

This endemic species is found only in Puerto Rico, making it a true island treasure. Its extremely limited geographical distribution contributes significantly to its vulnerable status—when a plant exists in only one location on Earth, any environmental change or habitat loss becomes an existential threat.

Should You Plant Ausu in Your Garden?

The short answer is: probably not, and here’s why. With so few individual plants remaining in the wild, every single ausu is precious for the species’ survival. Unless you’re working with a legitimate conservation program or botanical institution with proper permits and responsibly sourced material, attempting to cultivate this species could potentially harm conservation efforts.

Instead of trying to grow ausu, consider these alternatives:

• Support Puerto Rican conservation organizations working to protect endemic species
• Plant other native Puerto Rican species that aren’t critically endangered
• Create habitat gardens that support local wildlife and pollinators
• Participate in citizen science projects that help monitor rare plant populations

The Mystery of Growing Conditions

One of the challenges with extremely rare plants like ausu is that we simply don’t have enough information about their specific growing requirements, propagation methods, or garden performance. This knowledge gap exists precisely because the species is so rare—there haven’t been opportunities for extensive cultivation trials or horticultural research.

How You Can Help

While you can’t responsibly grow ausu in your backyard, you can still play a role in its conservation:

• Learn about and support habitat preservation efforts in Puerto Rico
• Choose native plants for your own region to support local ecosystems
• Share information about rare plant conservation with fellow gardeners
• Consider donating to botanical gardens or conservation organizations working with endangered species

A Reminder About Rarity

Ausu serves as a powerful reminder that not every beautiful plant belongs in our gardens. Sometimes, the most meaningful way to appreciate a species is to ensure it continues to exist in its natural habitat for future generations to discover and protect. In the case of this critically endangered Puerto Rican endemic, our role as gardeners is to be stewards and advocates rather than cultivators.

The next time you’re planning your native plant garden, remember the ausu—not as a plant you should grow, but as an inspiration to choose responsibly sourced native species that support conservation rather than compromise it.