Caryopsis
A caryopsis is a dry, one-seeded fruit whose seed coat is fused to the fruit wall. Wheat, rice, and maize grains are caryopses.
Fruit: A mature plant ovary, sometimes accompanied by other floral tissues, that contains seeds. A caryopsis is a specialized fruit, despite often being called a seed.
Wheat: A group of cereal grasses cultivated for their edible grains, used chiefly to make flour. Each wheat kernel is a caryopsis with bran, endosperm, and embryo.
Cereal: A grass cultivated for its edible grain, including wheat, rice, maize, barley, and oats. Cereal crops produce caryopses as their harvested grains.
Nut (fruit): A dry, indehiscent fruit with a hard wall and usually one seed. A nut has a distinct fruit wall, unlike the fused wall and seed coat of a caryopsis.
Pericarp: The mature ovary wall that forms the outer tissues of a fruit. In a caryopsis, the pericarp is fused to the seed coat.
Rice: A cereal grass cultivated for its starchy seeds, which are a staple food worldwide. The rice grain is a caryopsis enclosed by removable husks.
Bran: The nutrient-rich outer layers removed from cereal grains during milling. Much of cereal bran comes from the caryopsis pericarp and associated seed layers.
Samara: A dry fruit with a wing-like extension that aids wind dispersal. A samara disperses by its winged fruit wall rather than resembling a cereal grain.
Seed coat: The protective outer covering of a seed, formed from the ovule's integuments. Its fusion with the pericarp is the defining feature of a caryopsis.
Maize: A cereal grass whose large edible seeds grow in rows on a cob. Each maize kernel is a caryopsis, with pericarp fused to seed coat.