is romaine hearts the same as romaine lettuce
Romaine or cos lettuce (Lactuca sativa L. var. longifolia) is a variety of lettuce that grows in a tall head of sturdy dark green leaves with firm ribs down their centers. Unlike most lettuces, it is tolerant of heat. It is more nutritious than iceberg lettuce. In North America, romaine is sold as whole heads or as ``hearts'' that have had the outer leaves removed and are often packaged together.
Romaine lettuce