Romaine Lettuce

Romaine lettuce is a tall, crisp-headed lettuce with elongated leaves and sturdy, pale ribs. Its ribs deliver a snappy crunch and a mild, slightly bitter green flavor that stands up to creamy dressings and high heat; use it for Caesar salads, chopped salads, lettuce wraps, or to grill halved heads. Sold as whole heads or trimmed hearts.

Originating in the Mediterranean and often called cos after the island of Kos, it spread through Europe and became a staple in North American salads. Growers cultivate it as a cool-season field crop with staggered plantings, with production shifting by region to keep supplies consistent.