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

Spirodela polyrhiza (L.) Schleiden, orth. var.
great duckweed
Lemnaceae

Introduction to Vascular Plants

© Jamie Fenneman  Email the photographer   (Photo ID #11427)

E-Flora BC Static Map
Distribution of Spirodela polyrhiza
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Species Information

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General:
Fronds annual, free-floating, round to egg-shaped, (3) 5-10 mm long, purplish beneath, stalked, in single or small groups, 5- to 11-nerved, with 5 to 15 rootlets.
Flowers:
Usually 3 per pouch, 2 male, 1 female, enclosed in 2 lateral budding pouches sheathed by a minute membrane.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Ponds and slow-moving streams in the lowland, steppe and montane zones; frequent in SW and SC BC, infrequent elsewhere except absent on N Vancouver Island, the Queen Charlotte Islands and NW BC; circumpolar, E to PQ and NS and S to FL, MS, TX, NM, AZ, CA and MX; Eurasia, S America.

Source: The Illustrated Flora of British Columbia

Ecology

Ecological Framework for Spirodela polyrhiza

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

Minimum

Average

Maximum

Elevation (metres) 420 589 758
Slope Gradient (%) 0 0 0
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
0
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
7 7 8
Modal Nutrient Regime
Class
E
Number of field plots
 species was recorded in:
2
Modal BEC Zone Class
BG
All BEC Zones (# of stations/zone) species was recorded in: BG(1), IDF(1)

Climate

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

Lemna polyrrhiza L.
Spirodela polyrhiza
Spirodela polyrrhiza var. masonii Daubs

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References