American Bistort, Snakeweed, Mountain Meadow Knotweed, Western Bistort
Bistorta bistortoides
Synonyms: Persicaria bistortoides, Polygonum bistortoides, Polygonum bistortoides var. linearifolium, Polygonum bistortoides var. oblongifolium, Polygonum cephalophorum, Polygonum glastifolium, Polygonum vulcanicum
American bistort blooming along FS Road #27 in Thompson Valley, Fremont National Forest.......May 19, 2016.
Characteristics:
American bistort is an erect perennial arising 30-60 cm from
a thick tuber. The basal leaves are long petiolate and not jointed to the stem.
The leaf blade is oblong-lanceolate or wider, to 15 cm long. The stipules are
brownish and 3-6 cm long. There are a few lanceolate stem leaves, reduced in
size upwards on the stem. The inflorescence is a terminal raceme, spike-like,
from 3-6 cm longand 1-2 cm wide. It is densely white-flowered as seen in the
photo above.
Habitat:
American bistort is a montane species found in moist or swampy
meadows, streambanks, or alpine slopes.
Range:
American bistort is found from southern Alaska to southern California,
east to Alberta, Montana, and New Mexico.
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American bistort blooming along a small creek along the South Loop Road about one mile downhill from the East Rim Viewpoint, Steens Mountain, Harney County, Oregon........August 31, 2011.
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American bistort observed in bloom along FS Road 4215 about 100 meters south of the junction with FS Road 4220, Ochoco National Forest.......May 19, 2018.
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The photo at left shows a close-up of the inflorescence of american bistort as seen on moist grassland slopes in Zumwalt Prairie between Buckhorn Lookout and Enterprise, OR........June 27, 2008. The photo at right shows a close-up of the inflorescence of american bistort about 2.5 miles upstream along the upper Sycan River from the trailhead along the Hanan Trail #142, Fremont-Winema National Forest.....June 17, 2020..
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American bistort as seen at the north trailhead for Baldy Mountain, Malheur National Forest........July 1, 2010.
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A wet meadow full of american bistort as seen about one mile downhill from the Kiger Gorge Overlook, Steens Mountain, Harney County, Oregon........August 31, 2011. The photo at right shows a late blooming american bistort as seen in wet riparian meadows along the South Loop Road about one mile west of the East Rim Viewpoint, Steens Mountain..........September 20, 2015.
Paul Slichter