Lettuce is an annual plant of the family Asteraceae. It is most often grown as a leaf vegetable, but sometimes for its stem and seeds. Lettuce is most often used for salads, although it is also seen in other kinds of food, such as soups, sandwiches and wraps; it can also be grilled. One variety, celtuce, is grown for its stems, which are eaten either raw or cooked. In addition to its main use as a leafy green, it has also gathered religious and medicinal significance over centuries of human consumption. Europe and North America originally dominated the market for lettuce, but by the late 20th century the consumption of lettuce had spread throughout the world. As of 2021, world production of lettuce and chicory was 27 million tonnes, 53 percent of which came from China.
Leucanthemum vulgare, commonly known as the ox-eye daisy, oxeye daisy, dog daisy, marguerite and other common names, is a widespread flowering plant native to Europe and the temperate regions of Asia, and an introduced plant to North America, Australia and New Zealand.
Lactucarium is the milky fluid secreted by several species of lettuce, especially Lactuca virosa, usually from the base of the stems. It is known as lettuce opium because of its sedative and analgesic properties. It has also been reported to promote a mild sensation of euphoria. Because it is a latex, lactucarium physically resembles opium, in that it is excreted as a white fluid and can be reduced to a thick smokable solid.
Lactuca virosa is a plant in the Lactuca (lettuce) genus, often ingested for its mild analgesic and sedative effects. It is related to common lettuce, and is often called wild lettuce, bitter lettuce, laitue vireuse, opium lettuce, poisonous lettuce, tall lettuce, great lettuce or rakutu-karyumu-so.
Cornus canadensis is a species of flowering plant in the dogwood family Cornaceae, native to eastern Asia and North America. Common names include Canadian dwarf cornel, Canadian bunchberry, quatre-temps, crackerberry, and creeping dogwood. Unlike its relatives, which are for the most part substantial trees and shrubs, C. canadensis is a creeping, rhizomatous perennial growing to about 20 centimetres tall.
Sanguisorba minor, the salad burnet, garden burnet, small burnet, burnet, pimpernelle, Toper's plant, and burnet-bloodwort, is an edible perennial herbaceous plant in the family Rosaceae. It has ferny, toothed-leaf foliage; the unusual crimson, spherical flower clusters rise well above the leaves on thin stems. It generally grows to 25–55 cm tall. The large, long, taproots store water, making it drought-tolerant.
Lactuca serriola, also called prickly lettuce, milk thistle, compass plant, and scarole, is an annual or biennial plant in the tribe Cichorieae within the family Asteraceae. It has a slightly fetid odor and is commonly considered a weed of orchards, roadsides and field crops. It is the closest wild relative of cultivated lettuce.
Emilia sonchifolia, also known as lilac tasselflower or cupid's shaving brush, is a tropical flowering species of tasselflower in the sunflower family. It is widespread in tropical regions around the world, apparently native to Asia and naturalized in Africa, Australia, the Americas, and various oceanic islands.
Cicerbita alpina, commonly known as the alpine sow-thistle or alpine blue-sow-thistle is a perennial herbaceous species of plant sometimes placed in the genus Cicerbita of the family Asteraceae, and sometimes placed in the genus Lactuca as Lactuca alpina. It is native to upland and mountainous parts of Europe.
Lactuca biennis is a North American species of wild lettuce known by the common names tall blue lettuce and blue wood lettuce. It is widespread across much of the United States and Canada from Alaska and Yukon south as far as California, New Mexico, and Georgia.
Lactuca saligna is a species of wild lettuce known by the common name willowleaf lettuce, and least lettuce. It is native to Eurasia but it grows in many other places as an introduced species, including much of North America.
Lactuca muralis, the wall lettuce, is a perennial flowering plant in the tribe Cichorieae within the family Asteraceae, also referred to as Mycelis muralis.
Balsamorhiza sagittata is a North American species of flowering plant in the tribe Heliantheae of the family Asteraceae known by the common name arrowleaf balsamroot. Also sometimes called Oregon sunflower, it is widespread across western Canada and much of the western United States.
Lactuca cypria, the Cyprus lettuce, is a biennial, erect herb with glandular, hairy stems and a globose rhizome. Leaves alternate, simple, the basal large, oblong, petiolate, 10-15 x 5–7 cm, pinnatisect with a suborbicular terminal lobe, the upper smaller, often with a profound purple colour at the lower surface. Flowers in heads, capitula in corymbs, florets pale yellow, all ligulate, flowers April–July, fruit a pappose achene.
Lactuca floridana, commonly known as woodland lettuce, Florida lettuce, or false lettuce is a North American species of wild lettuce. It is native across much of central Canada and the eastern and central United States.
Lactuca graminifolia, the grassleaf lettuce is a North American species of wild lettuce. It grows in Mexico, Central America, Hispaniola, and the southern United States from Arizona to Florida, Virginia and the Carolinas.
Lactuca hirsuta, the hairy lettuce, is a North American species of wild lettuce. It is widespread across much of central Canada and the eastern and central United States from Ontario, Québec, Prince Edward Island, and Nova Scotia south as far as Texas, Louisiana, and Florida.
Lactuca ludoviciana, the biannual lettuce, is a North American species of wild lettuce. It is widespread across much of central and western Canada and the western and central United States from Ontario west to British Columbia and south to Louisiana, Texas, and California. Most of the known populations are on the Great Plains; populations west of there may well represent naturalizations.
Lactuca quercina is a species of wild lettuce native to Europe and Asia. It is an annual or biennial herb in the tribe Cichorieae within the family Asteraceae growing from a taproot to maximum heights of 50–200 cm (19.5–78.5 in) or more.
Lactuca indica, the Indian lettuce, is a species of plant in the tribe Cichorieae within the family Asteraceae. It is native to western China, the Himalayas, and southwest Asia as far west as Turkey. It is widely introduced elsewhere, even as far as east Africa, and is thought to be an archaeophyte in Japan, brought in with rice cultivation.
