A fruit tree is a tree bearing fruit — the structures forme by the ripened ovary of a flower containing one or more seeds. However, because all trees of flowering plants produce fruit (essentially all trees except tree ferns and gymnosperms), the term in horticultural usage applies to trees providing fruit as human food. Types of fruits are described and defined elsewhere (see Fruit), but would include fruit in a culinary sense as well as some nut bearing trees, like walnuts.