North America Native Plant

Maxwell’s Girdlepod

Botanical name: Mitracarpus maxwelliae

USDA symbol: MIMA6

Life cycle: perennial

Habit: subshrub

Native status: Native to Puerto Rico  

Maxwell’s Girdlepod: A Critically Rare Puerto Rican Treasure Have you ever heard of Maxwell’s girdlepod? If not, don’t worry – you’re in good company. This tiny botanical gem, scientifically known as Mitracarpus maxwelliae, is one of Puerto Rico’s best-kept secrets, though not by choice. This remarkable little plant is fighting ...

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

Maxwell’s Girdlepod: A Critically Rare Puerto Rican Treasure

Have you ever heard of Maxwell’s girdlepod? If not, don’t worry – you’re in good company. This tiny botanical gem, scientifically known as Mitracarpus maxwelliae, is one of Puerto Rico’s best-kept secrets, though not by choice. This remarkable little plant is fighting for survival in its native homeland.

What Makes Maxwell’s Girdlepod Special?

Maxwell’s girdlepod is a perennial forb – basically a non-woody plant that comes back year after year. Think of it as nature’s version of a hardy wildflower, though this one happens to be incredibly rare. As a member of the forb family, it lacks the woody stems you’d find on shrubs or trees, instead growing as a herbaceous plant with its growing points right at or below ground level.

Where in the World Can You Find It?

This little plant calls Puerto Rico home – and only Puerto Rico. It’s what botanists call an endemic species, meaning it evolved in this specific location and exists nowhere else on Earth naturally. Talk about being a homebody!

The Reality Check: Why You Probably Shouldn’t (and Can’t) Grow It

Here’s where we need to have a serious conversation. Maxwell’s girdlepod isn’t just rare – it’s critically imperiled. With a Global Conservation Status of S1, this plant is hanging on by a thread. In the United States, it’s officially listed as Endangered, which means there are typically fewer than 1,000 individuals left in the wild, possibly spread across just five or fewer locations.

What does this mean for you as a gardener? Simply put, this isn’t a plant you can (or should) casually add to your garden wish list. Even if you could somehow obtain seeds or plants, doing so without proper permits and conservation protocols could actually harm the species’ survival chances.

The Responsible Approach

If you’re fascinated by Maxwell’s girdlepod and want to help, here are some better ways to contribute:

  • Support conservation organizations working in Puerto Rico
  • Learn about and grow other native Puerto Rican plants that aren’t endangered
  • Spread awareness about the importance of protecting endemic species
  • If you live in Puerto Rico, participate in local habitat preservation efforts

Growing Conditions (What We Know)

Unfortunately, detailed growing information for Maxwell’s girdlepod is limited – partly because it’s so rare that few people have had the opportunity to study its cultivation needs extensively. What we do know is that it evolved in Puerto Rico’s unique climate, which falls roughly into USDA hardiness zones 11-12, characterized by warm temperatures year-round and distinct wet and dry seasons.

The Bigger Picture

Maxwell’s girdlepod serves as a powerful reminder of how fragile our planet’s biodiversity really is. While we can’t all grow this particular plant, we can all play a role in protecting the native species in our own backyards. Every time you choose a native plant over a non-native alternative, you’re helping create habitat and support the intricate web of life that makes our ecosystems function.

So while Maxwell’s girdlepod might not grace your garden beds, let it inspire you to discover and celebrate the native plants that do call your region home. After all, every place has its own botanical treasures – some more accessible than others, but all worth protecting for future generations to discover and admire.

Maxwell’s Girdlepod

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Rubiales

Family

Rubiaceae Juss. - Madder family

Genus

Mitracarpus Zucc. - girdlepod

Species

Mitracarpus maxwelliae Britton & P. Wilson - Maxwell's girdlepod

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