Buckwheat is a broad-leaved, erect, herbaceous plant that grows to a height of 0.7 to 1.5 meters. It has a main stem and several branches and can reach full maturity in 60 to 110 days. The stem is usually grooved, succulent, and hollow, except for the nodes. Before maturity, the stems and branches are green to red in color; after maturity, however, they become brown. The plant has a shallow taproot from which branched, lateral roots arise. Its root system is less extensive than those of cereals and constitutes only 3 to 4 percent of the dry weight of the total plant, which - in conjunction with the large leaf surface - may cause wilting during periods of hot and dry weather.
Buckwheat has an indeterminate flowering habit. The flowers of common buckwheat are perfect but incomplete. They have no petals, but the calyx is composed of five petal-like sepals that are usually white, but may also be pink or red. The flowers are arranged in dense clusters at the ends of the branches or on short pedicels arising from the axils of the leaves. Common buckwheat plants bear one of two types of flowers. The pin-type flower has long styles (or female parts) and short stamens (or male parts), and the thrum-type flower has long styles and short pistils. The pistil consists of a one-celled superior ovary and a three-part style with knoblike stigmas and is surrounded by eight stamens. Nectar-secreting glands are located at the base of the ovary. The plants of common buckwheat are generally self-infertile, as self-fertilization is prevented by self-incompatibility of the dimorphic, sporophitic type. Seed production is usually dependent on cross-pollination between the pin and thrum flowers. Honeybees and leaf-cutter bees are effective pollinators that increase seed set and seed yield.
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