A substantial eastern disjunction of Douglas’ Knotweed (Polygonum douglasii Greene, Polygonaceae) in New Brunswick, Canada

Authors

  • C. Sean Blaney Atlantic Canada Conservation Data Centre
  • Gart Bishop
  • Stephen R. Clayden
  • James P. Goltz

DOI:

https://doi.org/10.22621/cfn.v137i1.3115

Keywords:

Polygonum douglasii, Douglas' Knotweed, New Brunswick, Wisconsin, Alaska, Range disjunction

Abstract

We report an isolated population of the native annual Douglas’ Knotweed (Polygonum douglasii Greene) from a dry, south-facing outcrop of conglomerate and sandstone at Big Bluff, near Sussex Corner, New Brunswick, Canada, consisting of about 2500 plants in 2018 and 2022. This occurrence is disjunct by ~450 km from the eastern limit of the known range of Douglas’ Knotweed in southwestern Maine, USA. The nearest known occurrence in Canada is in southern Quebec, ~660 km from Big Bluff. Several lines of evidence indicate that the population in New Brunswick is native. New state records for Wisconsin and Alaska found in online data sources are also verified.

Author Biography

C. Sean Blaney, Atlantic Canada Conservation Data Centre

Executive Director & Senior Scientist

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Published

2024-01-15

Issue

Vol. 137 No. 1 (2023)

Section

Notes

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