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A seed is the ripened ovule of gymnosperm or angiosperm plants. The importance of the seed relative to more primitive forms of reproduction and dispersal is attested to by the success of these two groups of plants in dominating the landscape.

1 Seed structure

A seed contains the embryo from which a new plant will grow under proper conditions. It also contains a supply of stored food and is wrapped in a seed coat. The stored food begins as a tissue called endosperm derived from the parent plant. Endosperm becomes rich in oil or starch, and protein. In some species, the embryo is imbedded in the endosperm, which the seedling will use upon germination. In others, the endosperm is absorbed by the embryo as the latter grows within the developing seed, and the cotyledons of the embryo become filled with this stored food. At maturity, seeds of these species have no endosperm. Some common plant seeds that lack an endosperm are bean, pea, oak, walnut, squash, sunflowerSunflowers is also a painting by Vincent van Gogh. The sunflower Helianthus annuus is a large (to 3 m) annual plant in the Family Asteraceae with a flower head ( inflorescence) that is as much as 30 cm (1 ft) across and notable for turning to face towards, and radishThe radish Raphanus sativus is a vegetable of the Cruciferae family. The edible part, a bulb of white flesh, is the swollen underground stem just above the root (Latin radix it is a taproot). The skin comes in a variety of colours. Most commonly known is. Plant seeds with an endosperm include all coniferCordaitales Pinales Pinaceae Pine family Araucariaceae Araucaria family Podocarpaceae Yellow-wood family Sciadopityaceae Umbrella-pine family Cupressaceae Cypress family Cephalotaxaceae Plum-yew family Taxaceae Yew family Vojnovskyales Voltziales The conis and most monocotyledonBase Monocots: Acorus Alismatales Asparagales Dioscoreales Liliales Pandanales Family Petrosaviaceae Commelinids: Arecales Commelinales Poales Zingiberales Family Dasypogonaceae Monocotyledons or monocots are a group of flowering plants usually ranked ass (e.g. grassesSee: List of Poaceae genera The true grasses are monocot (class Liliopsida) plants of the family Poaceae (formerly Graminae . There are some 600 genera and perhaps 10,000 species of grasses. It is estimated grasslands comprise 20% of the vegetation cover and palmsmany, see text Arecaceae (formerly Palmae or Palmaceae is the Palm Family of flowering plants, belonging to the monocot order Arecales. The type member of this family is the areca palm, the fruit of which is chewed with the betel leaf and often confused w), and also e.g. brazil nutThe Brazil Nut is a South American tree Bertholletia excelsa in the family Lecythidaceae; it is the only species in the genus Bertholletia''. It is native to Guiana, Venezuela, Brazil, eastern Colombia, eastern Peru and eastern Bolivia. It occurs as scatt, castor bean.

The seed coat develops from tissues (called integument) originally surrounding the ovule. The seed coat in the mature seed can be a paper thin layer (for example, peanut) or something more substantial.

The seeds of angiosperms are contained in a hard or fleshy (or with layers of both) structure called a fruit. Gymnosperm seeds begin their development "naked" on the bracts of cones, although the seeds do become covered by the cone scales as they develop. An example of a hard fruit layer surrounding the actual seed is that of the so-called stone fruits (such as the peach).