Polygonum achoreum, common names Blake's knotweed, leathery knotweed or striate knotweed,Brako, L., A.Y. Rossman & D.F. Farr. 1995. Scientific and Common Names of 7,000 Vascular Plants in the United States 1–294. is a North American species of plants in the buckwheat family. It is widespread across much of Canada and the northern United States.Biota of North America Program 2014 state-level distribution map
Polygonum achoreum is an herb up to tall with yellow-green flowers in flat-topped clusters.Flora of North America, Polygonum achoreum S. F. Blake, 1917. Blake, Sydney Fay. 1917. Rhodora 19(226): 232–234 descriptions in English and Latin, commentary in English
References
External links photo of herbarium specimen at Missouri Botanical Garden, collected in Missouri in 1993