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Montana Field Guide

Montana Field Guides

Douglas Knotweed - Polygonum douglasii


Global Rank: G5
State Rank: S4

Agency Status
USFWS:
USFS:
BLM:
MNPS Threat Rank:
C-value: 3

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General Description
Annual. Stems erect or ascending, simple or branched, 5–35 cm. Leaves sessile, 5–40 mm long, linear to elliptic, reduced above; stipules glabrous, 4–10 mm long. Flowers 3–4 mm long, 1 to 4 in upper leaf axils; pedicels reflexed, 2–5 mm long; tepals green with white to pink margins. Achene 3-sided, 2–3 mm long, shiny black (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Species Range
Present
 


Range Comments
AK to CA, AZ, NM, IA and VA (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Summary of Observations Submitted for Montana
Number of Observations: 51

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density

Recency

 

(Observations spanning multiple months or years are excluded from time charts)



Habitat
Sparsely vegetated soil of stream banks, grasslands, open forest, roadsides; all elevations (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

References
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Citation for data on this website:
Douglas Knotweed — Polygonum douglasii.  Montana Field Guide.  .  Retrieved on , from