Flower profile

Western yellow pond-lily

Nuphar polysepala

Native in the lower 48

Western yellow pond-lily 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 May–August.

12states

2of our state lists

5,467U.S. sightings*

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

On our lists for: Alaska, Wyoming

Quick look

Nuphar polysepala, also known as the great yellow pond-lily, wokas, or wocus, is a perennial, rhizomatous, aquatic herb in the genus Nuphar. It has floating green leaves and yellow flowers.
From Wikipedia's article Nuphar polysepala, CC BY-SA 4.0.

It belongs to the Nymphaeaceae 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 12 states. ^{USDA PLANTS}
NatureServe lists it as native to Alaska and Wyoming. ^NatureServe
In Wyoming, most iNaturalist sightings of it in flower come in June–August. ^iNaturalist
USDA PLANTS lists its flower color as yellow. ^{USDA PLANTS}
USDA PLANTS gives its bloom period as spring. ^{USDA PLANTS}
USDA PLANTS lists a mature height of about 4 ft. ^{USDA PLANTS}
iNaturalist has 675 research-grade sightings of it in Alaska, ranking #65 among the 108 flowers on our Alaska list. ^iNaturalist
iNaturalist has 395 research-grade sightings of it in Wyoming, ranking #71 among the 107 flowers on our Wyoming list. ^iNaturalist

Western yellow pond-lily gift ideas

Handmade western yellow pond-lily gifts from independent makers.

🌱 Sample spot. Handmade gift picks from independent shops will appear here once our shop partnership is approved. These cards are placeholders, not real products.

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Western yellow pond-lily art print
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Western yellow pond-lily greeting card
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Western yellow pond-lily mug
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Western yellow pond-lily earrings
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Western yellow pond-lily embroidery pattern
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Western yellow pond-lily sticker
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When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (477 records)

Bloom time in each of our 2 states

State	Type	Peak bloom	Sightings*
Alaska	Native	few records	675
Wyoming	Native	June–August	395

Conservation status

Federal (U.S. ESA): Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. ^{USFWS ECOS}
NatureServe global: T5 See NatureServe for what T5 means. ^NatureServe
Alaska: No list Alaska has no state law listing endangered or threatened plants, so we show NatureServe's Alaska ranks instead. NatureServe: SNR, not yet ranked in Alaska.
Wyoming: No list Wyoming has no state law listing endangered or threatened plants, so we show NatureServe's Wyoming ranks instead. NatureServe: S3, vulnerable in Wyoming.
Rare elsewhere: Other states where NatureServe ranks it rare or missing: AZ (S1), NV (S1), 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.

Please leave it where it grows

Please don't pick or dig this flower: NatureServe ranks it S3 in Wyoming. ^NatureServe

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 Western yellow pond-lily in 12 states.

AKMEVTNHWAIDMTNDMNILWIMINYRIMAORNVWYSDIAINOHPANJCTCAUTCONEMOKYWVVAMDDEAZNMKSARTNNCSCDCOKLAMSALGAHITXFL

recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Alaska, Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, Wyoming.

Alaska counties with USDA records: Aleutians West, Anchorage, Bethel, Chugach, Copper River, Denali, Dillingham, Fairbanks North Star, Haines, Juneau, Kenai Peninsula, Kodiak Island, Lake and Peninsula, Matanuska-Susitna, Northwest Arctic, Sitka, Southeast Fairbanks, Yakutat, Yukon-Koyukuk.

Wyoming counties with USDA records: Albany, Big Horn, Carbon, Fremont, Johnson, Park, Sheridan, Sublette, Teton.

More Alaska flowers

Fireweed

Chamaenerion angustifolium

Native

🌼 Blooms in AK: June–August

Common cowparsnip

Heracleum maximum

Native

🌼 Blooms in AK: June–August

Common yarrow

Achillea millefolium

Native

🌼 Blooms in AK: June–September

Sources

USDA, NRCS. PLANTS Database, profile NULUP.
iNaturalist, Nuphar polysepala: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
Wikipedia, Nuphar polysepala (lead quoted under CC BY-SA 4.0).
Alaska: Alaska prohibited and restricted noxious weeds (11 AAC 34.020).
Wyoming: Wyoming state designated noxious weeds (W.S. 11-5-102(a)(xi)), as listed by the Wyoming Weed & Pest Council.
USFWS, ECOS species database (ESA listing check), October 17, 2026.
NatureServe Explorer, Nuphar polysepala (global and state ranks).
Edibility and toxicity: no source found (marked "not well documented").
Photo: Henrik Kibak via iNaturalist · CC BY 4.0 · resized.