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Greater Marsh St. John's-wort

Triadenum walteri

In the Carolinas and Georgia, found in swamp forests and marshes. Weakley, Flora of the Southeastern United States (2025), Carolinas & Georgia edition What its natural habitat tells you

66
Strong

Native to Louisiana (estimated). How scores work Is it native here?

Profile 88%

Height
Up to about 3 feet
Light
Partial shade, Full shade, Full sun
Soil moisture
Moist to wet
Will it fit your yard?

At a glance

Life cycle
Perennial
Bloom
July to September

Not yet recorded · Spread · Leaves

Recorded in 41 Louisiana parishes.

Natural habitats

Places it grows wild. Not a planting requirement. Each habitat page lists the plants and wildlife also found there.

1 of 2

Swamps

The Land of Evangeline
Joseph Rusling Meeker, The Land of Evangeline (1874): moss-hung trees over a still bayou in Louisiana swamp forest. Regional view: the painting does not name the exact site. Louisiana bayou country (Meeker, The Land of Evangeline, 1874)The Land of Evangeline, Joseph Rusling Meeker, 1874. Public domain. Source record. scaled to 1280 x 923 by the Wikimedia thumbnailer from 4096 x 2953; no crop or other change

Freshwater marshes

Open, herb-covered wetlands with fresh, non-tidal water.

All habitats

Also found with this plant

Wildlife whose habitat models include habitats this plant grows in, in Louisiana. Shared habitat, not food. 100 animals.

Widespread birds also seen here (34)

Found in many habitats here, so not listed above.

All wildlife of Louisiana

Ecological relationships

Who uses this plant?

What these records mean

14CaterpillarsGenus host records with ranges including LA

Genus host records with ranges including LA · Hypericum

  • Acleris maculidorsanaStained-Back Leafroller Moth
  • Choristoneura rosaceanaOblique-Banded Leafroller Moth, Rosaceous Leaf Roller
  • Eupithecia miserulataCommon Eupithacia, Common Pug
  • Iodopepla u-albumBurgundy St. Johnswort Moth, White-Eyed Borer
  • Iridopsis ephyrariaPale-Winged Gray
  • Mocis latipesSmall Mocis, Striped Grass Looper
  • Nedra ramosulaGray Half-Spot
  • Nemoria bistriariaTwo-Striped Emerald, Red-Fringed Emerald
  • Platynota flavedanaBlack-Shaded Platynota
  • Probole amicariaFriendly Probole
Show all 14
  • Sparganothis sulfureanaSparganothis Fruitworm Moth, Sulfur Leafroller, False Yellow-Head
  • Tallula watsoniWatson's Tallula
  • Zale lunataLunate Zale
  • Xenotemna pallorana
Shropshire & Tallamy 2025, Lepidoptera of North America north of Mexico, ZooKeys 1261 (ODbL)
43BeesSoutheastern regional records

Southeastern regional records · Hypericum

Individual names are not available yet.

Noori, Seltmann & Orr 2026, A curated and integrated dataset for exploring global bee-plant interactions (GloBI), Zenodo, CC BY 4.0
0Specialist beesPollen specialists
1BirdsRecorded eating Triadenum in Louisiana

Diet records by plant genus, from studies across North America. Not a record from this state. Birds whose range includes Louisiana, most records first.

Avian Diet Database (Hurlbert Lab)

Direct food only. Caterpillars on host plants also feed nesting birds. NC Native Plant Society: butterfly gardening

No records yet · Ants · Beetles · Flies · Adult butterflies / moths · Other wasps · Other insects

Birds that eat Triadenum 1

Diet records by plant genus, from studies across North America. Not a record from this state. Avian Diet Database (Hurlbert Lab), CC0 1.0.

Growing and identification

Plant details

Family
Hypericaceae
Flower color
White, pink or green

Safety has not been reviewed for this plant; check toxicity and thorns before planting.

Growing sources and scope
Also known as

Greater Marsh St. John's wort; Greater Marsh St. Johnswort; Hypericum walteri; john's wort; john's-wort

Conservation status

Louisiana rankSNR
Global rankG5
LA statusNot verified
Federal statusNot verified

Conservation source Global and federal source

In your garden

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Sources