What term describes a weed that produces seeds every two years?

The term for a weed that produces seeds every two years is "biennial." Biennial plants complete their life cycle over a two-year period. In the first year, they typically develop vegetative structures, such as leaves and roots, and then they enter a dormant phase during the winter. In the second year, these plants flower, produce seeds, and then die. This two-year lifecycle distinguishes biennials from annuals, which complete their lifecycle in one year, and perennials, which live for more than two years and can produce seeds multiple times throughout their lifespan. Understanding the life cycle of different types of plants, including weeds, is crucial for effective crop management and weed control strategies.