In milling the hull, which comprises 18 to 20 percent of the whole grain weight, is first removed. In most buckwheat flour some of the seed coat particles remain, resulting in a light brown color. More complete milling results in a white flour. The Japanese buckwheat is most widely grown in this country. The seeds are large, brown in color, and triangular in cross section.
Plants are tall, rather coarse growers with large, broad arrow-shaped leaves.
Silverhull plants are smaller than Japanese with smaller leaves. The seeds are small, nearly round in cross section, glossy and gray in color. The hulls are thinner than in Japanese. A kind tenned Common Gray is probably identical with Silverhull. Tartary buckwheat has small seeds, nearly round in cross section.