In eastern European cookery the hulled kernels, or groats, cooked and served much like rice, are called kasha, and in France they are called sayraisin. Buckwheat flour is unsatisfactory for bread because it lacks the elastic protein gluten and won't rise. It is used in the United States and Canada, alone or mixed with wheat flour, to make griddle cakes. Then picture shows ripening seeds of buckwheat. Notice the polygonal shape.
Brown seeds are mature.
Green seeds are still unripe. Buckwheat is either of two species, Fagopyrum esculentum, or sagittatum, and F. tataricum of herbaceous plants and their edible seeds, which are used as a cereal grain. The kernels of the triangular shaped seeds are enclosed by a tough, dark brown or gray rind. The white flowers are pollinated by bees and other insects. Although the seeds are used as cereal, the plant is not one of the cereal grasses.