Themes of Plant Biology
The Shoot System: Flowers, Fruits, Seeds
Seeds develop from ovules in the ovary, and at maturity consist of an embryo and a reserve food supply surrounded by a protective covering, the seed coat. The diversity of flowering plants assures diversity among their seeds, but, unlike fruits, which have numerous variations, structural plans for seeds are few. The reserve food can be stored either in or out of the embryo and the cotyledon(s)—the seed leaves—can remain either below ground or be elevated above the surface when germination occurs.
Fruits are ripened ovaries containing seeds with sometimes additional flower or inflorescence tissues associated with them. Only angiosperms produce flowers and fruits. From a botanical viewpoint, many of the foods we eat as vegetables are fruits, e.g. tomatoes, green beans, squash, eggplant, and peppers. Fruits apparently arose as a means not only of protecting the seeds, but as a way to ensure their dispersal.
