Editing Seed (section)

=== Embryo ===
[[File:Ginkgo embryo and gametophyte.jpg|thumb|The inside of a ''[[Ginkgo]]'' seed, showing a well-developed embryo, nutritive tissue ([[megagametophyte]]), and a bit of the surrounding seed coat]]

The main components of the embryo are:
* The '''[[cotyledon]]s''', the seed leaves, attached to the embryonic axis. There may be one ([[Monocotyledons]]), or two ([[Dicotyledons]]). The cotyledons are also the source of nutrients in the non-endospermic dicotyledons, in which case they replace the endosperm, and are thick and leathery. In endospermic seeds, the cotyledons are thin and papery. Dicotyledons have the point of attachment opposite one another on the axis.
* The '''[[epicotyl]]''', the embryonic axis above the point of attachment of the cotyledon(s).
* The '''plumule''', the tip of the epicotyl, and has a feathery appearance due to the presence of young leaf primordia at the apex, and will become the shoot upon germination.
* The '''[[hypocotyl]]''', the embryonic axis below the point of attachment of the cotyledon(s), connecting the epicotyl and the radicle, being the stem-root transition zone.
* The '''[[radicle]]''', the basal tip of the hypocotyl, grows into the primary root.

Monocotyledonous plants have two additional structures in the form of sheaths. The plumule is covered with a '''[[coleoptile]]''' that forms the first leaf while the radicle is covered with a '''[[coleorhiza]]''' that connects to the primary root and [[adventitious]] roots form the sides. Here the hypocotyl is a rudimentary axis between radicle and plumule. The seeds of corn are constructed with these structures; pericarp, scutellum (single large cotyledon) that absorbs nutrients from the endosperm, plumule, radicle, coleoptile, and coleorhiza&nbsp;– these last two structures are sheath-like and enclose the plumule and radicle, acting as a protective covering.