Horticulture/Lactuca

Lactuca, commonly known as lettuce, is a genus of flowering plants in the Sunflower family Asteraceae. The genus includes about 100 species, distributed worldwide, but mainly in temperate Eurasia.

Description
Its best-known representative is the garden lettuce (Lactuca sativa), with its many varieties. But many are just common weeds. They are annuals or perennials. Their height can vary between 10–180 cm. They form heads or capitula in panicles of yellow, brown or purple flowers in ray florets.

The non-edible species may contain bitter elements. Others contain a milky juice.

Species

 * ../Lactuca biennis/ : Tall Blue Lettuce, Wild Blue Lettuce
 * ../Lactuca canadensis/ : Canada Lettuce, Florida Blue Lettuce, Wild Lettuce (North America)
 * ../Lactuca sativa/ : Garden Lettuce, Lettuce
 * ../Lactuca serriola/ : Prickly Lettuce, China Lettuce, Wild Lettuce (Southern Europe)
 * ../Lactuca tatarica/ : Blue Lettuce, Chickory Lettuce, Russian Blue Lettuce (Asia, India)

Uses
The garden lettuce is grown as a salad green, other species occur as weeds.