noun, plural: seeds
(botany) An encapsulated plant embryo; a fertilized ovule of a plant
A seed is a fertilized ovule containing the plant embryo. Given the appropriate growth conditions, it will become the new plant. Thus, it is also regarded as the propagating organ particularly of spermatophytes (i.e. gymnosperms and angiosperms). Plants such as ferns, mosses, and liverworts do not produce seeds. Gymnosperms do not have ovaries and therefore produce naked seeds. Angiosperms produce seeds that are encapsulated by a protective outer covering (seed coat or testa) and food reserves (endosperm) as nutrient source of the growing embryo. The cotyledons of the plant embryo within the seed are used as a basis in classifying angiosperms. Dicots are angiosperms that have two cotyledons. Monocots are those with only one cotyledon.
Certain seeds are edible (e.g. legumes, nuts, and cereals). Edible seeds are an essential component of an animal diet due to its high content of concentrated nutrients, e.g. starches, proteins, and fats. Other seeds such as sunflower, rapeseed, and cottonseed are used commercially in the production of oils (fats).