North America Native Plant

Rio Loc Stickpea

Botanical name: Calliandra locoensis

USDA symbol: CALO15

Life cycle: perennial

Habit: shrub

Native status: Native to Puerto Rico  

Rio Loc Stickpea: A Critically Endangered Puerto Rican Native If you’ve stumbled across the name Rio Loc stickpea in your native plant research, you’ve discovered one of Puerto Rico’s botanical treasures—and one of its most endangered. The Rio Loc stickpea (Calliandra locoensis) is a rare gem that deserves our attention, ...

Rare plant alert!

Region: Conservation status by state

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) ⚘

Rio Loc Stickpea: A Critically Endangered Puerto Rican Native

If you’ve stumbled across the name Rio Loc stickpea in your native plant research, you’ve discovered one of Puerto Rico’s botanical treasures—and one of its most endangered. The Rio Loc stickpea (Calliandra locoensis) is a rare gem that deserves our attention, not for our gardens, but for conservation efforts.

What Makes Rio Loc Stickpea Special?

This perennial shrub is endemic to Puerto Rico, meaning it exists nowhere else on Earth. As a member of the Calliandra genus, it’s related to other beautiful flowering shrubs known for their distinctive powder-puff blooms that typically attract hummingbirds and other pollinators.

Rio Loc stickpea grows as a multi-stemmed woody shrub, usually staying under 13-16 feet tall. Like other shrubs, it typically develops several stems from or near the ground, though environmental conditions can sometimes lead to different growth patterns.

Where Does It Grow?

This species is found exclusively in Puerto Rico, making it a true island endemic. Its limited geographic distribution is part of what makes it so vulnerable to extinction.

A Plant in Crisis

Here’s the important part every plant lover needs to know: Rio Loc stickpea has a Global Conservation Status of S1, which means it’s critically imperiled. This classification indicates extreme rarity, with typically five or fewer known occurrences and very few remaining individuals (fewer than 1,000 plants total).

This level of rarity means that this species is teetering on the edge of extinction and requires immediate conservation attention.

Should You Grow Rio Loc Stickpea?

The short answer is: probably not, unless you’re involved in official conservation efforts. Here’s why:

  • Extreme rarity: With so few plants remaining in the wild, any cultivation should be part of coordinated conservation programs
  • Unknown cultivation requirements: Due to its rarity, there’s limited information about how to successfully grow this species
  • Responsible sourcing concerns: Any plant material should come from legitimate conservation programs, not wild collection

How You Can Help Instead

While you might not be able to grow Rio Loc stickpea in your garden, you can still support its conservation:

  • Support organizations working on Puerto Rican plant conservation
  • Choose other native Calliandra species that are more readily available
  • Spread awareness about the importance of protecting rare endemic species
  • If you live in Puerto Rico, consider volunteering with local botanical conservation groups

Alternative Native Options

If you’re drawn to the Calliandra genus for your native garden, look for other species that are more widely available and not threatened with extinction. These alternatives can provide similar ecological benefits without putting pressure on rare species.

The story of Rio Loc stickpea reminds us that some plants are too precious and too rare for casual cultivation. Sometimes the best way to appreciate a species is to ensure it survives in its natural habitat for future generations to discover and protect.

Rio Loc Stickpea

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

Fabales

Family

Fabaceae Lindl. - Pea family

Genus

Calliandra Benth. - stickpea

Species

Calliandra locoensis R. Garcia & D. Kolterman - Rio Loc stickpea

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