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

Polygonum minimum S. Watson
leafy dwarf knotweed (broadleaf knotweed)
Polygonaceae (Buckwheat family)

Introduction to Vascular Plants

© Ryan Batten  Email the photographer   (Photo ID #23924)

E-Flora BC Static Map
Distribution of Polygonum minimum
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Species Information

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Annual herb from a taproot; stems ascending to erect, several, branched, 3-15 cm tall, reddish, round in cross-section, grooved.
Basal leaves lacking; stem leaves alternate, elliptic to more or less round, the blades 5-25 mm long, the stalks very short or lacking; stipules translucent, 2-4 mm long, ragged.
Inflorescence of 2-3 flowers in axillary clusters; perianths 1.5-2 mm long, green with pinkish margins, 5-lobed about 2/3 the distance to the base.
Achenes, 3-angled, greenish-black, smooth, shiny, 2-2.5 mm long. barely exceeding the perianths.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Moist vernal sites to dry rocky slopes and forest openings in the lowland to alpine zones; infrequent in BC S of 55degreeN; E to AB and S to CO and CA.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Polygonum minimum

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) 5 466 1858
Slope Gradient (%) 1 38 84
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
60 206 335
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
0 3 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: CWH(31), ESSF(7), ICH(3), PP(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.

Taxonomic and Nomenclatural Links

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General References