Lactuca sativa, is by far the most popular of the leafy salad vegetables. The lettuce belongs to the very large family Compositae, which includes cultivated species such as chicory and endive, and various wild plants with edible leaves, all more or less tough and bitter, e.g. the dandelion and some thistles. The original wild lettuce, L. serriola, is still common in Europe and temperate Asia, and is as harsh as any of these. It is also called ‘prickly’ or ‘wood’ lettuce, an unpromising plant for cultivation.
The original reason for cultivating lettuce was probably medicinal. Wild lettuce and, to a lesser extent, its cultivated descendant contain a latex with a mildly soporific effect. This resembles and smells like the latex of the opium poppy, but the plants are not related.
Lettuce has a long history in the kitchen, beginning in the Near East. Ancient Egyptian tombstones of about 4500 bc show a plant which appears to be lettuce. It is impossible to be sure because early varieties were tall, spindly plants with a lot of stem, comparatively small leaves, and no proper head; and there are other plants of the lettuce and chicory group which have much the same form. (For this reason wild chicory has sometimes been called ‘wild lettuce’ in England.) The Greeks themselves, who called it tridax, were certainly using it not long afterwards. About 400 bc its dietary qualities were assessed in the Hippocratic text Regimen, and since it is mentioned by the other Greek writers on food it is clear that it was widely cultivated and eaten.
The Romans ate a lot of lettuce. The Latin name lactuca is connected with lac, milk, because of the milky sap or latex which oozes out of the cut stem. In the early Roman period lettuce was eaten at the end of a dinner to calm the diner and induce sleep. Later it was eaten at the beginning to stimulate appetite. This change would have coincided with the development of improved varieties which, selected for lack of bitterness, would have contained less of the narcotic substances. In the 1st century ad Pliny describes nine varieties including a purple and a red one. All these were still loose, headless types. The usual Roman way of serving lettuce was as a salad with a dressing, but Apicius also gives a recipe for a purée of lettuce and onions and Columella described how lettuce was pickled in vinegar and brine.
By the 5th century the plant was being cultivated in China, where it has always been treated as a vegetable to be cooked. Because of this different approach the lettuces which have been developed in China and the Far East have different characteristics.
Following the Dark Ages, lettuce does not appear again in European literature until the late 14th century, in the prologue to Chaucer's Canterbury Tales where we read: ‘well loved he garlic, onions and lettuce.’ However, it seems that during the Middle Ages it was the wild L. perennis, perennial lettuce, which was eaten in salads by peasants; while the ancestral prickly lettuce continued to be used medicinally, and as a soporific. Later, in the 16th century, the cultivated plant began to take on the forms known today. Both the round-headed lettuce and the cos type were then described for the first time.
Seventeenth-century writers also mention minor varieties: cut leafed, oak leafed, and with multiple heads like Brussels sprouts. Colours included light and dark green, red, and spotted. Some of these fancy plants have been revived.
Seeds of European lettuces were taken to the Americas as early as 1494 and importation continued thereafter. All American cultivated lettuces are of European ancestry, although there are wild American species, e.g. the Canada wild lettuce, L. canadensis. The wild plants are as harsh as their European relatives, and are not normally eaten.
By 1600 the narcotic effect of lettuce had been much reduced. It seems that the only known cases of lettuce having actually sent people into a stupor (unless one counts the Flopsy Bunnies, cited by Jane Grigson, 1978) are when, in times of shortage, they have been reduced to eating large amounts of the stems of lettuces which have ‘bolted’ or gone to seed.
These have been classified in various ways, mostly according to shape. The following main categories are recognized:
A special type of lettuce (L. sativa, Angustana Group) grown mainly in China is called ‘celtuce’ in English. The word is a combination of ‘celery’ and ‘lettuce’, given it because of its shape. Another, flattering, name is ‘asparagus lettuce’. The fleshy stem is the part eaten, usually cooked. The lower leaves, which are tough and unpalatable, are stripped off before the plant is sold, leaving only the tender leaves at the very top.
The Indian lettuce belongs to a different species, L. indica, and has been developed separately from L. sativa varieties. It is rather coarse, and has reddish leaves, or leaves with a red midrib.
In Japan a common type of lettuce, tsitsa, has been independently domesticated from a different wild lettuce. It is sometimes referred to by the botanical name L. tsitsa, although this has not been officially recognized.
So-called ‘miner's lettuce’ is purslane.
For the principal use of lettuce, see salads.
In the 17th century, as French works of the period testify, the cores of lettuces were candied to make a prized confection known as gorge d'ange (angel's throat).
Cream of lettuce soup is popular, but cooked lettuce is not generally favoured in western countries, although it is common practice to cook peas with a little lettuce.
In China lettuce leaves are shredded and stir-fried. Celtuce stems are peeled and finely sliced crosswise before cooking; the tops are used like ordinary lettuce.
Alan Davidson was a distinguished author and publisher, and one of the world's best-known writers on fish and fish cookery. In 1975 he retired early from the diplomatic service—after serving in, among other places, Washington, Egypt, Tunisia, and Laos, where he was British Ambassador—to pursue a fruitful second career as a food historian and food writer extraordinaire. Among his popular books are Seafood of South-East Asia, North Atlantic Seafood, and Mediterranean Seafood. In 2003, shortly before his death, he was awarded the Erasmus Prize for his contribution to European culture.
Grigson, Jane (1978), Jane Grigson's Vegetable Book, London: Michael Joseph.
