[Knotweeds: The Genus Polygonum in the Cascade Mountains of Oregon and Washington]
Douglas' Knotweed, Austin's Knotweed
Polygonum douglasii
Synonyms: Polygonum douglasii ssp. douglasii, Polygonum douglasii var. douglasii, Polygonum douglasii var. latifolium, Polygonum montanum
The photo above shows a close-upsof
the leaves and flowers of Douglas' knotweed as seen along road #6000 at about
2780' on the southeastern slopes of Mt. Adams..........May 29, 2005.
Note that the tepals are cleft more than one-half their length.
The photo above shows a close-upsof the leaves and flowers of Douglas' knotweed as seen along road #6000 at about 2780' on the southeastern slopes of Mt. Adams.........May 29, 2005. Note that the tepals are cleft more than one-half their length.
The photo above shows the form of a young Douglas' knotweed. This species is an annual, so the roots are not well developed. Photographed in dry duff soils next to a riparian area to the east of the Mt. Adams Highway...........May 13, 2007.
Paul Slichter
