Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn) and wild buckwheat (Polygonum convolvulus L.) are annual weeds which are becoming increasingly prevalent on the Canadian prairie. Tartary buckwheat has become widespread in north central Alberta where over 2,500,000 acres are estimated to be infested, with over 500,000 acres heavily infested. The infested area is growing larger and in recent years has begun spreading into the neighboring province of Saskatchewan. Only one infestation, some 300 acres in size, has been reported in Manitoba. Because it is similar in size, the seed of tartary buckwheat is extremely difficult to remove from wheat, oats and barley and under the Canada Seeds Act, grains containing it may not be sold for seed. Commercial grain containing these seeds is severely degraded. As an impurity in wheat, the seed causes discolored flour. Consequently, the spread of this weed is being viewed with considerable alarm in western Canada.