Wheat grain. Light micrograph with drak ground illumination of a vertical section through a grain of wheat (Triticum vulgare). This is the fruit of the plant, and includes the endosperm (larger area, blue), which is full of food in the form of starch grains and protein crystals. The seed (smaller area at upper right, pink) contains the embryo. The embryonic area includes a plumule and radicle enclosed within the coleoptile and coleorhiza respectively. The plumule and radicle are the structures by which the seed will germinate and develop a root and leaf system, developing into a new plant. The endosperm provides nutrients for the germinating plant. Wheat is a crop that is cultivated for its grains, which are a rich source of starch.