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
An additional photo of american bistort:
Photo from Mt Rainier National Park- August 23, 19
Paul Slichter