Flower profile

Golden bean

Thermopsis rhombifolia

Golden bean (Thermopsis rhombifolia) is a flowering plant in the Fabaceae family, native in the lower 48 states, blooming mostly April–June across the U.S.

Native in the lower 48

Golden bean is a wildflower that USDA PLANTS lists as native in the lower 48 states. It's on our flower lists for 2 states, and across the U.S. it's most often seen in bloom in April–June.

10states where USDA records it

2Bloomipedia state lists include it

1,505U.S. sightings*

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

On our lists for: North Dakota, South Dakota

Quick look

Thermopsis rhombifolia, also known as prairie thermopsis, is a species of flowering plant in the legume family. It is native to North America, where it is found in the Great Plains, with extensions into the lower canyons of the Rocky Mountains. Its natural habitat is dry grasslands and woodlands.
From Wikipedia's article Thermopsis rhombifolia, CC BY-SA 4.0.

It belongs to the Fabaceae family. ^iNaturalist
USDA PLANTS describes it as an herb (forb) with a perennial life cycle. ^{USDA PLANTS}
USDA PLANTS lists it as native in the lower 48 states and records it in 10 states. ^{USDA PLANTS}
NatureServe lists it as native to South Dakota and North Dakota. ^NatureServe
iNaturalist has 390 research-grade sightings of it in South Dakota, ranking #30 among the 126 flowers on our South Dakota list. ^iNaturalist
iNaturalist has 131 research-grade sightings of it in North Dakota, ranking #55 among the 116 flowers on our North Dakota list. ^iNaturalist

When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (76 records)

Bloom time in the 2 states whose Bloomipedia list includes it

State	Type	Peak bloom	Sightings*
South Dakota	Native	few records (12)	390
North Dakota	Native	few records (20)	131

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
South Dakota: No list South Dakota's endangered and threatened list (ARSD 41:10:02) covers animals only, so we show NatureServe's South Dakota ranks for plants. NatureServe: SNR, not yet ranked in South Dakota.
North Dakota: No list North Dakota has no state law listing endangered or threatened plants, so we show NatureServe's North Dakota ranks instead. NatureServe: SNR, not yet ranked in North Dakota.
Rare elsewhere: Other states where NatureServe ranks it rare or missing: UT (S2). (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 golden bean in 10 states.

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recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Colorado, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, Utah, Wisconsin, Wyoming.

South Dakota counties with USDA records: Butte, Custer, Fall River, Harding, Jackson, Lawrence, Meade, Mellette, Pennington, Perkins, Walworth.

North Dakota counties with USDA records: Billings, Bowman, Burke, Burleigh, Divide, Dunn, Emmons, Golden Valley, Grant, Hettinger, Logan, McKenzie, Mercer, Morton, Mountrail, Oliver, Slope, Stark, Ward, Williams.

Names, range and relatives

Native status by region (USDA PLANTS): Canada: Native; Lower 48 states: Native.

Other scientific names (synonyms in USDA PLANTS): Thermopsis arenosa.

County records: USDA PLANTS lists it in 122 counties across 9 states; the most are in Montana (41), North Dakota (20), Wyoming (18).

More from the Fabaceae family (114 on Bloomipedia; most observed first): Lupines, White clover, Red clover, Eastern redbud, Purple crownvetch, Bird's-foot trefoil, Partridge pea, White sweetclover.

More South Dakota flowers

Leadplant

Amorpha canescens

Native

🌼 Few flowering records in SD

Yellow sweetclover

Melilotus officinalis

Introduced

🌼 Few flowering records in SD

Wild licorice

Glycyrrhiza lepidota

Native

🌼 Few flowering records in SD

Sources

USDA, NRCS. PLANTS Database, profile THRH.
iNaturalist, Thermopsis rhombifolia: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
Wikipedia, Thermopsis rhombifolia (lead quoted under CC BY-SA 4.0).
South Dakota: South Dakota statewide noxious weeds (ARSD 12:62:03:01.06).
North Dakota: North Dakota state noxious weeds (N.D. Admin. Code 7-06-01-02), as listed by the ND Department of Agriculture.
USFWS, ECOS species database (ESA listing check), October 17, 2026.
NatureServe Explorer, Thermopsis rhombifolia (global and state ranks).
Edibility and toxicity: no source found (marked "not well documented").
Photo: Bob Walker via iNaturalist · CC BY 4.0 · resized.