caryopsis(n = noun.plant) grain - dry seed-like fruit produced by the cereal grasses: e.g. wheat, barley, Indian corn;
is a kind of seed
has particulars: amaranth, barleycorn, wheat berry, kernel, rye

   A one-celled, dry, indehiscent fruit, with a thin membranous pericarp, adhering closely to the seed, so that fruit and seed are incorporated in one body, forming a single grain, as of wheat, barley, etc. [1913 Webster]

caryopsis, n. (pl. caryopses) Bot. a dry one-seeded indehiscent fruit, as in wheat and maize.

Etymology:
mod.L f. Gk karuon nut + opsis appearance