Like all plants, lettuce has different parts that make up the plant. You generally grow lettuce as a vegetable, although it does produce attractive flowers if not harvested.
The root of lettuce is below the soil, like most other plants. The roots gather nutrients from the soil to feed and nourish the plant during its growing stages.
The stem is the thick part of the vegetable attached to the roots and above the soil. When you harvest lettuce, you generally cut it off at the stem.
The leaves of lettuce are what you typically eat. For most lettuces, you eat them raw in salads or in sandwiches. Popular lettuce varieties include butterhead, iceberg and romaine.
Lettuce typically blooms approximately two to three months after it emerges from the ground. Prior to and during blooming, the lettuce plant's stem will grow longer and produce branches. Lettuce plants produce many yellow flowers, most of which open in the morning and close at night. The flowering stage lasts approximately three to four weeks.