Page authors: Don Knoke, David Giblin
Nuphar polysepala
yellow pond lily, spatterdock

Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east to Northwest Territory, Alberta, and the Rocky Mountain States.

Habitat: Ponds, shallow lakes, oxbows, and sluggish streams from low to middle elevations.

Flowers: May-August

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Beetles, flies


Aquatic, perennial herbs with thick rhizomes bearing directly the flowers and leaves.


Leaves mostly floating, the terete petiole up to 2 m. long, the cordate blade 1-4 dm. long and about 2/3 as wide, leathery.


Flowers solitary, showy, long-pedunculate, perfect; sepals usually 9, the outer ones leathery, greenish, and shorter than the bright yellow inner ones, which are 3.5-6 cm. long, obovate and truncate; petals 10-20, thick, lanceolate, greenish-yellow, much smaller that the sepals, nearly equaling the numerous reddish or purplish stamens; style 1; stigma 13- to 25-rayed, 2-2.5 cm. broad.


Capsule ovoid, 5-9 cm. long, prominently ribbed

Accepted Name:
Nuphar polysepala Engelm.
Publication: Trans. Acad. Sci. St. Louis. 2: 282. 1865.

Synonyms & Misapplications:
Nuphar lutea (L.) Sm., misapplied
Nuphar lutea (L.) Sm. ssp. polysepala (Endelmann) E.O. Beal [KZ99]
Nuphar polysepalum Engelm. [HC]
Additional Resources:

PNW Herbaria: Specimen records of Nuphar polysepala in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Nuphar polysepala checklist entry.

OregonFlora: Nuphar polysepala information.

E-Flora BC: Nuphar polysepala atlas page.

CalPhotos: Nuphar polysepala photos.

USDA Plants: Nuphar polysepala information.

53 photographs:
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