Achene

Achene, a dry, indehiscent, single-seeded fruit. The term is often restricted to fruits like those of the common dock, resulting from a superior ovary, the wall of which does not adhere to the seed. But it is perhaps better to extend the term achene to all dry, indehiscent fruits, including forms like grains of wheat, 'seeds' of dandelions, nuts of hazel, and so on. See FRUIT.