An annual plant is a plant that completes its life cycle, from germination to the production of seeds, within one growing season, and then dies. Globally, only 6% of all plant species and 15% of herbaceous plants are annuals. The annual life cycle has independently emerged in over 120 different plant families throughout the entire angiosperm phylogeny.

In botany, a seed is a plant embryo and food reserve enclosed in a protective outer covering called a seed coat (testa). More generally, the term "seed" means anything that can be sown, which may include seed and husk or tuber. Seeds are the product of the ripened ovule, after the embryo sac is fertilized by sperm from pollen, forming a zygote. The embryo within a seed develops from the zygote and grows within the mother plant to a certain size before growth is halted.