North America Native Plant

Puerto Rico St. Johnswort

Botanical name: Hypericum diosmoides

USDA symbol: HYDI

Life cycle: perennial

Habit: forb

Native status: Native to Puerto Rico  

Puerto Rico St. Johnswort: A Little-Known Native Gem If you’re looking to support Puerto Rico’s native plant heritage, you might want to get acquainted with Puerto Rico St. Johnswort (Hypericum diosmoides). This perennial herb belongs to the fascinating St. Johnswort family, though it’s quite a bit more mysterious than its ...

Puerto Rico St. Johnswort: A Little-Known Native Gem

If you’re looking to support Puerto Rico’s native plant heritage, you might want to get acquainted with Puerto Rico St. Johnswort (Hypericum diosmoides). This perennial herb belongs to the fascinating St. Johnswort family, though it’s quite a bit more mysterious than its better-known cousins.

What Makes This Plant Special?

Puerto Rico St. Johnswort is a true Puerto Rican native – meaning it evolved right there in the Caribbean and calls those islands home. As a perennial forb, it’s an herbaceous plant that comes back year after year, without developing the woody stems you’d see in shrubs or trees. Think of it as a hardy, non-woody plant that keeps its growing points close to or below ground level.

Where You’ll Find It Growing Wild

This St. Johnswort is exclusively native to Puerto Rico, making it a special piece of the island’s botanical puzzle. You won’t find it growing wild anywhere else in the world – talk about island exclusivity!

The Water Connection

Here’s something interesting: Puerto Rico St. Johnswort has a facultative wetland status in the Caribbean region. This means it’s quite the flexible plant – while it usually prefers to hang out in wetland areas, it’s adaptable enough to handle drier conditions too. Think of it as a plant that likes to keep its options open when it comes to moisture levels.

Should You Grow It?

If you’re gardening in Puerto Rico or a similar tropical climate, supporting native plants like this St. Johnswort can be a wonderful way to:

  • Support local ecosystems and wildlife
  • Preserve Puerto Rico’s unique botanical heritage
  • Grow plants that are naturally adapted to the local climate
  • Reduce the need for excessive watering or fertilizing

However, there’s a catch – and it’s a big one. Information about cultivating Puerto Rico St. Johnswort is quite limited. This could mean it’s either rarely cultivated, challenging to grow, or simply hasn’t received much attention from the gardening world yet.

The Growing Challenge

Unfortunately, specific growing instructions for Puerto Rico St. Johnswort are scarce. What we do know is that it’s adapted to Puerto Rico’s tropical climate and can handle both wetland and somewhat drier conditions. If you’re determined to try growing it, you might want to:

  • Mimic its natural wetland habitat with consistent moisture
  • Provide partial shade, as many understory native plants prefer
  • Use well-draining soil that doesn’t become waterlogged
  • Contact local Puerto Rican botanical gardens or native plant societies for guidance

A Word of Caution

Because so little is known about this plant’s cultivation requirements and availability, it’s possible that Puerto Rico St. Johnswort is uncommon or faces conservation challenges. If you’re interested in growing it, make sure any plants or seeds you acquire are responsibly sourced and not collected from wild populations.

The Bottom Line

Puerto Rico St. Johnswort represents the kind of unique, native plant that makes island ecosystems so special. While we’d love to give you a complete growing guide, this little herb remains something of a botanical mystery. If you’re a Puerto Rican gardener interested in native plants, it might be worth reaching out to local experts to learn more about this intriguing species – you might just become one of the few people successfully growing this island endemic!

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

FACW

Facultative Wetland - Plants with this status usually occurs in wetlands but may occur in non-wetlands

Puerto Rico St. Johnswort

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

Theales

Family

Clusiaceae Lindl. - Mangosteen family

Genus

Hypericum L. - St. Johnswort

Species

Hypericum diosmoides Griseb. - Puerto Rico St. Johnswort

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