Drupes are fruits with four major parts: a thin skin, a fleshy body, a hard stone, and an inner seed. Many are also edible, with people eating the various parts, depending on which kind it is. A surprising number of foods are considered drupes, ranging from almonds to peaches. Most cultures eat several different varieties, some of which play a major culinary role. They can generally be farmed or cultivated, although it is also possible to collect wild versions.
Working from the outside in, the first layer of a drupe is a thin skin or exocarp that protects it from the elements. Next comes the mesocarp, a thick layer of fleshy material that is often made juicy and sweet to appeal to animals, so that animals will eat the fruit and then spread the seeds in their feces. Next comes the stone or endocarp, which is extremely hard to protect the delicate seed inside. When the seed lands in good growing conditions, it will sprout, cracking the endocarp.
Stone fruits, such as plums, cherries, dates, mangoes, and apricots, are all part of this classification. In this case, people eat both the skin and the sweet flesh inside, but discard the bitter and inedible pit and seed. In other cases, people eat only the seed, in the form of foods like walnuts and almonds, which are usually culinarily classified as nuts because of their fleshy texture and high fat content.
Some people might be surprised to learn that some berries are also drupes. Raspberries and blackberries, for example, are made up of a cluster of tiny drupelets grouped around a central stem. People may have noticed that, when they get a raspberry seed stuck in their teeth, it is surprisingly hard, and it yields a small white kernel when cracked.
To be technical, fruits are also ovaries. An ovary is a female reproductive part that holds eggs that are capable of being fertilized. In plants, these eggs are called ovules, and when they are pollinated, they develop into fruits. Like many other fruits, drupes consist of the ovary and the ripened flesh around it, which protects the seeds and promotes dispersal. Obviously, plants are capable of generating new ovaries, unlike mammals.