A tender, dark green leaf, which adds a mild, slightly sweet and crunchy texture to all sorts of salads. Romaine is also called Cos which is an alternative spelling to Kos, as in the Greek Island, which is where Romaine lettuce is believed to have originated. The Cos leaf is best known from the Caesar Salad and rumour has it that this was invented by Caesar and Alex Cardini, brothers who ran a restaurant in Mexico during the Prohibition era. When a Fourth of July rush wiped out their kitchen supplies, the brothers combined the ingredients on hand, tossing them tableside for extra flair, and the Caesar salad was born!