Plants that grow, reproduce and die all in one season are called annuals.
An annual plant completes its entire life cycle within a single growing season: it germinates from a seed, develops leaves and roots, flowers, produces new seeds, and then dies. The phrase “one season” usually means one favorable period for growth, not necessarily one calendar year.
Annuals include peas, wheat, rice, sunflowers, marigolds and many weeds. Their short lives make rapid growth and seed production especially important. Many annuals survive unfavorable conditions not as living plants but as dormant seeds in the soil, sometimes forming a long-lasting seed bank.
Annuals are commonly contrasted with biennials, which normally take two growing seasons to complete their life cycle, and perennials, which live for several years and may reproduce repeatedly. Some plants can behave differently depending on climate: a species that is annual in a cold region may survive as a perennial in warmer conditions.