North America Native Plant

Puerto Rico Ridgerunner

Botanical name: Cybianthus sintenisii

USDA symbol: CYSI

Life cycle: perennial

Habit: shrub

Native status: Native to Puerto Rico  

Synonyms: Grammadenia sintenisii (Urb.) Mez (GRSI)   

Puerto Rico Ridgerunner: A Mysterious Native Wetland Shrub Meet the Puerto Rico ridgerunner (Cybianthus sintenisii), one of the Caribbean’s most elusive native shrubs. If you’re scratching your head wondering why you’ve never heard of this plant, you’re not alone – this perennial woody wonder is about as mysterious as native ...

Puerto Rico Ridgerunner: A Mysterious Native Wetland Shrub

Meet the Puerto Rico ridgerunner (Cybianthus sintenisii), one of the Caribbean’s most elusive native shrubs. If you’re scratching your head wondering why you’ve never heard of this plant, you’re not alone – this perennial woody wonder is about as mysterious as native plants get!

What Exactly Is a Puerto Rico Ridgerunner?

The Puerto Rico ridgerunner is a perennial shrub that’s completely native to Puerto Rico. Like most shrubs, it’s a multi-stemmed woody plant that typically stays under 13-16 feet tall, though it can occasionally stretch taller or even grow as a single stem depending on where it decides to set up shop.

You might also see this plant listed under its scientific synonym Grammadenia sintenisii in older botanical references, but Cybianthus sintenisii is the current accepted name.

Where Does It Call Home?

This shrub is endemic to Puerto Rico, meaning it’s found nowhere else on Earth. Talk about island exclusivity! It grows naturally throughout various parts of the island, making it a true Puerto Rican original.

A Wetland Specialist

Here’s where things get interesting (and a bit challenging for most gardeners): the Puerto Rico ridgerunner is classified as an Obligate Wetland species in the Caribbean region. This means it almost always occurs in wetland environments – think consistently moist or waterlogged soils that most garden plants would absolutely hate.

Should You Grow It?

While supporting native plants is always admirable, the Puerto Rico ridgerunner presents some unique challenges:

  • It requires specialized wetland conditions that are difficult to replicate in typical garden settings
  • Very little information is available about cultivation requirements, propagation methods, or care tips
  • Its specific growing needs and aesthetic qualities are largely undocumented
  • It may be quite rare, though its exact conservation status is unclear

The Reality Check

If you’re in Puerto Rico and have a naturally wet area on your property, you might already have this shrub growing wild! However, for most gardeners looking to add native Puerto Rican plants to their landscapes, you’ll probably have better luck with other native species that are better understood and more readily available.

The Puerto Rico ridgerunner serves as a fascinating reminder of how much we still don’t know about our native plant communities. Sometimes the most important thing we can do for rare native species is to protect their existing wild habitats rather than attempt cultivation.

The Bottom Line

While we can’t provide specific growing tips for this mysterious native, we can celebrate its existence as part of Puerto Rico’s unique botanical heritage. If you’re passionate about Puerto Rican native plants, consider supporting habitat conservation efforts or connecting with local botanical organizations that might have more specialized knowledge about this elusive ridgerunner.

Sometimes the best garden plants are the ones we admire from afar while working to protect their wild homes!

Wetland Status

The rule of seasoned gardeners and landscapers is to choose the "right plant for the right place" matching plants to their ideal growing conditions, so they'll thrive with less work and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection is. While tags list watering requirements, there's more to the story.

Knowing a plant's wetland status can simplify the process by revealing the interaction between plants, water, and soil. Surprisingly, many popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. Also, it helps you make smarter gardening choices and grow healthy plants with less care and feeding, saving you time, frustration, and money while producing an attractive garden with greater ecological benefits.

Regions
Status
Moisture Conditions

Caribbean

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Puerto Rico Ridgerunner

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Dilleniidae

Order

Primulales

Family

Myrsinaceae R. Br. - Myrsine family

Genus

Cybianthus Mart. - cybianthus

Species

Cybianthus sintenisii (Urb.) G. Agostini - Puerto Rico ridgerunner

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