Page author: Don Knoke
Potamogeton praelongus
white-stalked pondweed, whitestem pondweed

Distribution: Alaska south on both sides of the Cascades to California, east through Canada to Newfoundland, south to New York and Indiana.

Habitat: In the Pacific Northwest, mostly in deep water of lakes.

Flowers: May - July

Origin: Native

Conservation Status: Not of concern


Aquatic, herbaceous perennials from slender rhizomes, the stems up to 3 m. long, sparingly branched, slightly flattened, 2-3 mm. thick, whitish, the shorter internodes zigzag.


Leaves all submersed, the blades sessile, with a clasping base, oblong-lanceolate, 1-2.5 dm. long and 2-3 cm. broad, entire, the tip rounded and somewhat hooded; stipules free of the blade, 4-10 cm. long, whitish.


Flowers perfect, in dense spikes 2.5-5 cm. long; peduncles club-shaped, 1-3 dm. long; perianth of 4 clawed segments, each with an upturned, oval blade; stamens 4, fused with the claws; pistils 4, sessile.


Achenes obovoid, 4-5 mm. long, with a short beak and prominent dorsal keel.

Accepted Name:
Potamogeton praelongus Wulfen
Publication: Arch. Bot. (Leipzig). 3: 331. 1805. 1805.

Synonyms & Misapplications:
(none provided)
Additional Resources:

PNW Herbaria: Specimen records of Potamogeton praelongus in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Potamogeton praelongus checklist entry.

E-Flora BC: Potamogeton praelongus atlas page.

CalPhotos: Potamogeton praelongus photos.

USDA Plants: Potamogeton praelongus information.

8 photographs:
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