What is the embryo of a seed made of?

In all higher spore and seed plants, the embryo is the main structural element of the seed. The embryo consists of an embryonic stalk (hypocotyl), an embryonic root, an embryonic bud, and embryonic leaves (one or two cotyledons). The embryo stalk and root form the axis of the embryo. Cotyledons are attached to the top of the stem. The part of the stem above the cotyledons is epicotyl, and below it is the hypocotyl. At the very top of the stem is the embryonic bud, which is the rudiment of a new shoot, and the main root of the plant is formed from the embryonic root.