Which of the following best describes a "perennial" plant?

A perennial plant is characterized by its ability to grow and bloom for multiple years from the same root system after being planted only once. This resilience means that perennials typically come back year after year without the need for replanting, establishing a strong root system that allows them to survive through varying seasons. They often bloom in cycles over the years and can contribute to a stable garden or ecosystem by providing consistent growth and flowers season after season.

The other descriptions do not accurately reflect the nature of perennial plants. For instance, replanting every two years implies a need for replacement, which is a characteristic of biennials. Similarly, requiring replanting every year refers to annuals, which complete their life cycle in a single season and need to be replanted each year for continued growth. The last option, which states that the plant only blooms for a single season, inaccurately describes the long-term blooming potential of perennials.