During the development of the fruit, the wall of the ovary, called per carp, usually thickens and becomes differentiated into three layers, which may or may not be easy to distinguish visually. These layers are called the Exocarp, Mesocarp, and endocarp. As an example, in the peach, the Exocarp is the skin, the Mesocarp is the fleshy part, and the endocarp is the stony pit. The seed, containing the embryo, is inside the pit.

Fruit matured ovary of the pistil of a flower, also containing the seed. After the egg nucleus, has been fertilized (see fertilization) and the actual embryo plantlet begins to form, the surrounding ovule (see pistil) develops into the seed and ovary wall (pericap) around the ovule forms the fruit. Per carp consists of three layers of tissue; the thin outer Exocarp, which becomes the “skin” the thicker Mesocarp; and the inner endocarp, immediately surrounding the ovule. A flower may have one or more simple pistils (each called a carpel); different arrangements give rise to different types of fruit. A new variety of fruit is obtained as a hybrid in plant breeding or may develop spontaneously by mutations.

Example to describe the parts of the fruits with Tomato Fruit.

More special seed structural features:

• Hilum and funiculus: Funicular scar on seed coat that marks the point at which the seed was attached via the funiculus to the ovary tissue.
• Micropyle: The Micropyle is a canal or hole in the coverings (seed coat) of the nucellus through which the pollen tube usually passes during fertilization. Later, when the seed matures and starts to germinate, the micropyle serves as a minute pore through which water enters. The micropylar seed end has been demonstrated to be the major entry point for water during tobacco seed imbibition and germination. During germination the tobacco testa ruptures at the micropylar end and the radicle protrudes through the micropylar endosperm.
• Chalaza: Non-micropylar end of the seed. The base of an ovule, bearing an embryo sac surrounded by integuments.
• Raphe: Ridge on seed coat formed from adnate funiculus.
• Arillate: General term for an outgrowth from the funiculus, seed coat or chalaza; or a fleshy seed coat.
• Aril: Outgrowth of funiculus, raphe, or integuments; or fleshy integuments or seed coat, a sarcotesta. Arils probably often aid seed dispersal, by drawing attention to the seed after the fruit has dehisced, and by providing food as an attractant reward to the disperser. The aril of the nutmeg produces the spice mace and the seed itself is the nutmeg.
• Strophiole: Outgrowth of the hilum region which restricts water movement into and out of some seeds. In some hard-coated legume seeds, e.g. Melilotus alba and Trigonella arabica, a plug covering a special opening - the strophiolar cleft - must be loosened or removed before water can enter, and then only through this region.
• Operculum: A little seed lid. It refers to a dehiscent cap of a seed or a fruit that opens during germination.
• Carunculate: Seed with an excrescent outgrowth from integuments near the hilum, as in Euphorbia.
• Fibrous: Seed with stringy or cord-like seed coat, as mace in Myristica.
• Funicular: Seed with a persistent elongate funiculus attached to seed coat, as in Magnolia.
• Strophiolate: Seed with elongate aril or strophiole in the hilum region.
• Fruit: Strictly, the ripened ovary of a plant and its contents. More loosely, the term is extended to the ripened ovary and seeds together with any structure with they are combined, e. g. the apple (a pome) in which the fruit (core) is surrounded by flesh derived from the floral receptacle.
• Achene: A small, usually single-seeded, dry indehiscent fruit, e.g. lettuce.
• Caryopsis: A dry, nut-like fruit typical of grasses, e. g. a cereal grain. It is an achene with the ovary wall united with the seed coat.
• Elaiosomes: A specialty in the dispersal through animals is that through ants (myrmecochory). Such seeds or fruits bear attachments, the elaiosomes that contain lures and nutriments. Myrmecochory is common with plants that live at the forest soil like violets (Viola).
• Caruncle: A reduced aril, in the form of a fleshy, often waxy or oily, outgrowth near the hilum of some seeds. Usually it is brightly colored. It acts as an aid to dispersal. Viola seeds have an oily caruncle and are sought and dispersed by ants.
• Mucilage: A layer of polysaccharide slime produced by some seeds upon imbibition. Serves in water uptake during imbibition and germination.



Non-endospermic seeds
Fabaceae - Core Eudicots - Rosid clade		pea (Pisum sativum) garden bean (Phaseolus vulgaris) soybean (Glycine max)		The legume family (Fabaceae) has most of the species including pea (Pisum sativum) and diverse beans which have non-endospermic seeds. The cotyledons provide as sole food storage organs as in the case of pea (Pisum sativum). During embryo development the cotyledons absorb the food reserves from the endosperm completely. In the mature seed the embryo is enclosed solely by the testa as the only seed covering layer. The regulation by ethylene of pea seed germination and seedling emergence has been studied in detail.
Brassicaceae - Core Eudicots - Rosid clade		rape (Brassica napus) wild mustard (Sinapis alba) wild radish (Raphanus sativus)		The mustard family (Brassicaceae) species including several Brassica-species have non-endospermic seeds. The cotyledons serve as sole food storage organs as described for the non-endospermic Fabaceae seeds.

Seeds with perisperm
Amaranthaceae (incl. Chenopodiaceae) - Core Eudicots - Caryophyllid clade		sugar beet (Beta vulgaris) lambsquarters (Chenopodium album)		Perisperm is diploid maternal food storage tissue that originates from the nucellus. It is present in mature seeds of many Caryophyllales (Centrospermae) including the Amaranthaceae (Beta, Chenopodium) among the eudicots, but also in basal angiosperms like black pepper (Piper nigrum), Piperaceae.