Affixes

Seed-bearing plants are divided into two groups, the gymnosperms (Greek gumnos, naked), whose seeds are unprotected by an ovary or fruit, and the angiosperms (Greek angeion, vessel), a much larger group that has flowers and seeds enclosed within a carpel. Other botanical terms in this ending include endosperm (Greek endon, within), the part of a seed which acts as a food store for the developing plant embryo, and perisperm (Greek peri, about, around), a mass of nutritive material in some seeds that lies outside the embryo sac. The pteridosperms (Greek pteris, pterid‑, fern) are a type of fossil plants intermediate between the ferns and seed-bearing plants, which died out in the Triassic period.