E-Flora BC: Electronic Atlas of the Flora of British Columbia

Zannichellia palustris L.
horned pondweed
Potamogetonaceae (Horned pondweed family)
(Previously in Zannichelliaceae)

Introduction to Vascular Plants

© Mike Russum  Email the photographer   (Photo ID #65715)

E-Flora BC Static Map
Distribution of Zannichellia palustris
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Species Information

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Perennial, aquatic herb from slender rhizomes; stems threadlike, freely branching, 20-50 cm long.
Stem leaves opposite, threadlike, 1-nerved, 2-10 cm long, less than 1 mm wide, the tips abruptly pointed, membranous-sheathing at the base.
Inflorescence of male and female flowers in the axils, sometimes not together; the female flowers mostly of 3-5 carpels, unstalked or short stalked with a subtending bract shorter than the pistils; male flowers a single stamen.
Achenes, stalked, the backs curved, the fronts smooth or sharply toothed, beaked, the beaks 1 mm long.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Shallow, often alkaline or brackish lakeshores, slow-moving streams and tidal marshes in the lowland, steppe and montane zones; frequent in BC south of 54 degrees N, less frequent northward and on Vancouver Island; cosmopolitan, E to NF and NS and S to FL, TN, TX, MX; S America, Eurasia, Africa.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Zannichellia palustris

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres) 676 843 1010
Slope Gradient (%) 0 1 3
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
7 7 7
Modal Nutrient Regime
Number of field plots
 species was recorded in:
Modal BEC Zone Class
All BEC Zones (# of stations/zone) species was recorded in: BG(1), IDF(1)


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

Synonyms and Alternate Names

Zannichellia major (Hartm.) Boenn. ex Rchb.
Zannichellia palustris var. major (Hartman) W.D.J. Koch
Zannichellia palustris var. stenophylla Aschers. & Graebn.

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References