North America Native Plant

Claspingleaf St. Johnswort

Botanical name: Hypericum gymnanthum

USDA symbol: HYGY

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Claspingleaf St. Johnswort: A Hidden Gem for Wetland Gardens If you’re looking to add a splash of cheerful yellow blooms to your wetland garden or rain garden, claspingleaf St. Johnswort (Hypericum gymnanthum) might just be the native perennial you’ve been searching for. This understated beauty belongs to the St. Johnswort ...

Rare plant alert!

Region: New Jersey

Status: Endangered, Listed Pinelands, Highlands Listed, S1: New Jersey Highlands region ⚘ New Jersey Pinelands region ⚘ 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. ⚘

Claspingleaf St. Johnswort: A Hidden Gem for Wetland Gardens

If you’re looking to add a splash of cheerful yellow blooms to your wetland garden or rain garden, claspingleaf St. Johnswort (Hypericum gymnanthum) might just be the native perennial you’ve been searching for. This understated beauty belongs to the St. Johnswort family and brings both ecological value and delicate charm to moisture-loving landscapes.

What Makes Claspingleaf St. Johnswort Special?

Claspingleaf St. Johnswort is a native herbaceous perennial that’s perfectly adapted to life in wet places. As a forb—basically a fancy term for a non-woody flowering plant—it lacks the thick stems of shrubs but makes up for it with its specialized ability to thrive where many other plants would drown.

This native gem is found naturally across 22 states, stretching from the Northeast down through the Southeast and west into the Great Plains. You’ll find it growing wild in states like Florida, Georgia, Pennsylvania, Illinois, and Texas, among others.

A Word of Caution: Rarity Matters

Before you rush out to plant claspingleaf St. Johnswort, there’s something important to know. In New Jersey, this species is listed as Endangered with an S1 rarity status, meaning it’s critically imperiled in that state. If you live in New Jersey or other areas where it might be rare, please only source this plant from reputable native plant nurseries that propagate their own stock—never collect from the wild.

Garden Appeal and Landscape Role

Claspingleaf St. Johnswort produces small, bright yellow flowers with five petals that bloom during the summer months. While the individual flowers might be modest in size, they create a lovely display when planted in groups. The plant’s low-growing, herbaceous nature makes it perfect for:

  • Rain gardens and bioswales
  • Wetland restoration projects
  • Native plant gardens with consistent moisture
  • Bog gardens and pond edges
  • Natural areas that stay wet

Growing Conditions: All About the Water

This plant is definitely not for your typical perennial border! Claspingleaf St. Johnswort has very specific moisture requirements that vary slightly by region:

  • Moisture: Consistently wet to moist soil is essential
  • Sunlight: Full sun to partial shade
  • Soil: Tolerates various soil types as long as they stay moist
  • Hardiness: Zones 5-9 based on its natural distribution

In most regions, this species is classified as an Obligate Wetland plant, meaning it almost always occurs in wetlands. In some coastal areas, it’s listed as Facultative Wetland, which means it usually grows in wet areas but can occasionally tolerate drier conditions.

Wildlife and Pollinator Benefits

Like other members of the St. Johnswort family, claspingleaf St. Johnswort attracts small bees and other beneficial insects with its bright yellow blooms. While it might not be a major pollinator magnet like some showier natives, it plays its part in supporting local ecosystems, especially in wetland habitats where specialized pollinators depend on native plants.

Planting and Care Tips

Once you’ve sourced your plants responsibly, claspingleaf St. Johnswort is relatively low-maintenance:

  • Planting time: Spring or fall
  • Spacing: Allow room for natural spreading in wet conditions
  • Watering: Keep consistently moist—this is non-negotiable!
  • Maintenance: Minimal once established in proper conditions
  • Propagation: Can self-seed in ideal conditions

Is Claspingleaf St. Johnswort Right for Your Garden?

This native perennial is perfect for gardeners who:

  • Have consistently wet or boggy areas to plant
  • Are working on wetland restoration or rain garden projects
  • Want to support native ecosystems with appropriate plants
  • Appreciate subtle, naturalistic beauty over flashy displays

However, it’s not the best choice if you have typical garden soil that drains well or if you’re looking for a drought-tolerant native. This plant’s superpower is thriving in wet conditions where other plants struggle.

Claspingleaf St. Johnswort proves that sometimes the most specialized plants make the biggest impact in the right setting. If you have the wet conditions it craves and can source it responsibly, this native perennial will reward you with cheerful summer blooms and the satisfaction of supporting local wildlife in their preferred habitat.

Claspingleaf 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 gymnanthum Engelm. & A. Gray - claspingleaf 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