Polygonum majus (Meisn.) Piper
wiry knotweed
Polygonaceae (Buckwheat family)
Introduction to Vascular Plants
wiry knotweed
Polygonaceae (Buckwheat family)
Introduction to Vascular Plants
Species Information
General:
Annual herb from a small taproot; stems ascending to erect, numerous, simple to freely branched, 10-40 cm tall.
Leaves:
Basal leaves lacking; stem leaves alternate, linear to narrowly oblong, egg-shaped or elliptic, the blades 1-8 cm long, unstalked or nearly so, sometimes reduced to bracts above; stipules short-sheathing, 5-12 mm long, clear, becoming ragged.
Flowers:
Inflorescence of few flowers in elongate axillary racemes; perianths 1.5-5 mm long, greenish with white or pinkish margins, 5-lobed nearly to the base.
Fruits:
Achenes, lanceolate to egg-shaped, sometimes 3-angled, black, smooth and shiny, 2-4 mm long.
Illustration
If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.
Illustration Source: The Illustrated Flora of British Columbia
Ecology
Ecological Framework for Polygonum majus
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)
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 |
||
|
Avg |
Min |
Max |
|
| Elevation
(metres) |
691 | 350 | 1180 |
| Slope
Gradient (%) |
30 | 4 | 70 |
|
Aspect (degrees) |
198 | 20 | 334 |
| Soil
Moisture Regime (SMR) [0 - very xeric; 4 - mesic; 8 - hydric] |
2 | 1 | 5 |
| Modal
Nutrient Regime
Class |
C | ||
| #
of field plots species was recorded in: |
29 | ||
| Modal
BEC Zone Class |
PP | ||
|
All BEC Zones (# of stations/zone) species was recorded in |
BG(7), ICH(1), IDF(5), PP(13) | ||
|
Source:
Klinkenberg 2013
|
|||
Habitat and Range
Dry grasslands, shrublands, rocky slopes and forest openings in the steppe and montane zones; infrequent in SC BC; S to ID, W MT and CA.Status Information
Synonyms
Synonyms and Alternate Names:
Polygonum coarctatum var. majus Meisn.
Polygonum douglasii subsp. majus (Meisn.) J.C. Hickman