Page author: Hattie Palmer
Potamogeton berchtoldii
Berchtold's pondweed

Flowers: Late June - August

Origin: Native

Conservation Status: Not of concern


Herbaceous wetland perennial; cauline stems round to slightly compressed, spots absent, up to 150 cm, glands present on some or many nodes, to 0.5 mm diameter; turions common, soft, lateral or terminal, 0.9-3.2 cm long and 0.3-1.8 mm broad.


Leaves submersed, generally spirally arranged, sessile, fine to coarse; stipules persistent, inconspicuous, convolute, blade 0.9-5.4 cm long and 0.2-2.5 mm broad, linear, not curved, base somewhat tapered, lobes absent and not clasping, margins entire and not wavy, apex subulate to obtuse, not hoodlike, lacunae in 1-5 rows on each side of midrib, veins usually 1-3.


Inflorescence an unbranched, capitate to cylindric spike, 1.5-10.1 mm, above or below water surface; peduncles more than 3 per plant, terminal or emerging from axils, erect, uncommonly curved backward, cylindric to slightly clavate, more than 3 per plant.


Tepals 4, in 1 series; stamens usually 4, with distinct anthers dehiscing vertically, pollen spheric; pistils 1 or 4, usually lacking stipes but sometimes short-stipitate.


Drupes ovoid with rounded sides, 1.5-2.2 mm long and 1.2-1.6 mm broad, uncommonly concave; not keeled; beak erect, median, rarely near upper edge.

Accepted Name:
Potamogeton berchtoldii Fieber

Synonyms & Misapplications:
Potamogeton berchtoldii Fieber var. colpophilus (Fernald) Fernald
Potamogeton berchtoldii Fieber var. lacunatus (Hagstr.) Fernald
Potamogeton berchtoldii Fieber var. polyphyllus (Morong) Fernald
Potamogeton berchtoldii Fieber var. tenuissimus (Mertens & W.D.J. Koch) Fernald
Potamogeton pusillus L. ssp. tenuissimus (Mertens & W.D.J. Koch) R.R. Haynes & Hellq. [FNA22]
Potamogeton pusillus L. var. tenuissimus Mertens & W.D.J. Koch [JPM]
Additional Resources:

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

WA Flora Checklist: Potamogeton berchtoldii checklist entry.

E-Flora BC: Potamogeton berchtoldii atlas page.

CalPhotos: Potamogeton berchtoldii photos.

USDA Plants: Potamogeton berchtoldii information.

5 photographs:
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