Lactuca, commonly known as lettuce, is a genus of flowering plants in the family Asteraceae. The genus includes at least 50 species, distributed worldwide, but mainly in temperate Eurasia.
Its best-known representative is the garden lettuce (Lactuca sativa), with its many varieties. "Wild lettuce" commonly refers to the wild-growing relatives of common garden lettuce. Many species are common weeds. Lactuca species are diverse and take a wide variety of forms. They are annuals, biennials, perennials, or shrubs.[2] Their flower heads have yellow, blue, or white ray florets. Some species are bitter-tasting.
Most wild lettuces are xerophytes, adapted to dry habitat types. Some occur in more moist areas, such as the mountains of central Africa.[2]
Diversity
There are different concepts of the species within Lactuca. It is not clear how many distinct species are known, and estimates vary from 50[1] to 75[3] so far.
^ abLebeda, Aleš; Dolezalová, Ivana; Feráková, Viera; Astley, Dave (2004). "Geographical Distribution of Wild Lactuca Species (Asteraceae, Lactuceae)". The Botanical Review. 70 (3): 328–356. doi:10.1663/0006-8101(2004)070[0328:GDOWLS]2.0.CO;2.