romaine lettuce

vegetable

Also known as: cos lettuce

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Last updated

July 16, 2026

Quick Summary

Romaine lettuce, also known as cos lettuce, is a variety of garden lettuce (Lactuca sativa var. longifolia). It is an annual leaf vegetable characterized by its long, crisp leaves that form tall, oblong, loose heads. Romaine lettuce is commonly eaten fresh and serves as a popular base for green salads. It is a good source of vitamins K and A, although nutritional content can vary by specific variety. The name "romaine" comes from the French word for Roman.12

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lettuce
…shape; and (4) cos, or romaine, lettuce (variety longifolia), with smooth leaves that form a tall, oblong, loose head. There are two classes of head lettuce: the butterhead types, such as Bibb lettuce, with soft heads of thick oily-textured leaves, and crisphead types, such as iceberg lettuce, with brittle-textured leaves…
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…shape; and (4) cos, or romaine, lettuce (variety longifolia), with smooth leaves that form a tall, oblong, loose head. There are two classes of head lettuce: the butterhead types, such as Bibb lettuce, with soft heads of thick oily-textured leaves, and crisphead types, such as iceberg lettuce, with brittle-textured leaves…
Read More