Bloomipedia
Swamp loosestrife (Decodon verticillatus)
Photo: Lucy Keith-Diagne via iNaturalist · CC BY 4.0 · resized

Flower profile

Swamp loosestrife

Decodon verticillatus

Native to Rhode Island

Swamp loosestrife is a flowering plant that USDA PLANTS lists as native in the lower 48 states.

32states
161RI sightings*
7,848U.S. sightings*

*iNaturalist research-grade observations, as of October 17, 2026.

On our lists for: Rhode Island

Quick look

Decodon verticillatus, the sole living species in the genus Decodon, is a flowering plant in the family Lythraceae. It is commonly known as waterwillow or swamp loosestrife. It is native to wetlands in the eastern half of the United States and Canada.

  • It belongs to the Lythraceae family. iNaturalist
  • USDA PLANTS describes it as a shrub / a subshrub with a perennial life cycle. USDA PLANTS
  • USDA PLANTS lists it as native in the lower 48 states and records it in 32 states. USDA PLANTS
  • NatureServe lists it as native to Rhode Island. NatureServe
  • USDA PLANTS lists its flower color as red. USDA PLANTS
  • USDA PLANTS gives its bloom period as mid summer. USDA PLANTS
  • USDA PLANTS lists a mature height of about 8 ft. USDA PLANTS
  • iNaturalist has 161 research-grade sightings of it in Rhode Island, ranking #96 among the 110 flowers on our Rhode Island list. iNaturalist

Swamp loosestrife gift ideas

Handmade swamp loosestrife gifts from independent makers.

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When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (577 records)

There are only a handful of Rhode Island flowering records, so this chart uses records from across the U.S.

Conservation status

Federal (U.S. ESA)
Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. USFWS ECOS
NatureServe global
G5 Secure worldwide. NatureServe
Rhode Island
Not listed Not on Rhode Island Rare Plants 2016 (RI Natural History Survey, from the RI Wildlife Action Plan; informational, Rhode Island has no state plant-protection listing law). NatureServe: SNR, not yet ranked in Rhode Island. RI rare plants 2016
Rare elsewhere
Other states where NatureServe ranks it rare or missing: IA (S1), MO (S1), MS (S2), WV (S1). (S1 critically imperiled, S2 imperiled, SH possibly extirpated, SX presumed extirpated.)

Checked October 17, 2026. Rankings and lists can change, so follow the links for the latest.

Can you eat it?

For peopleNot well documented

None of the sources we checked (NC State Extension (no page for this plant), USDA PLANTS) say whether it's edible or poisonous for people.

For petsNot well documented

It isn't on the ASPCA plant list.

🌿 Never eat a wild plant unless you're certain of its ID; this isn't medical advice. Worried about a person? Call Poison Control at 1-800-222-1222. Worried about a pet? Call your vet.

Where does it grow?

USDA PLANTS records swamp loosestrife in 32 states plus Washington, D.C.

recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Alabama, Arkansas, Connecticut, Delaware, Florida, Georgia, Illinois, Indiana, Iowa, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Vermont, Virginia, West Virginia, Wisconsin; District of Columbia.

Rhode Island counties with USDA records: Newport, Providence, Washington.

More Rhode Island flowers

Purple loosestrife (Lythrum salicaria)

Purple loosestrife

Lythrum salicaria

Introduced

🌼 Blooms in RI: July–October
Roses (genus Rosa) (Rosa)

Roses (genus Rosa)

Rosa

★ NY state flower🌷 Garden flower

🌼 Blooms in RI: May–August
Rugosa rose (Rosa rugosa)

Rugosa rose

Rosa rugosa

Introduced

🌼 Blooms in RI: May–October

Sources