Lactuca virosa L. (Bitter Lettuce): In Vitro Culture and Production of Sesquiterpene Lactones

Lactuca virosa L. (family Asteraceae), also known as Lactuca silvestris Lam. or Wiestia virosa C.H. Schultz, is indigenous to south west Europe, North Africa and West Asia, and is also distributed in other regions of the Northern Hemisphere, including America. It grows singly or in clusters, on rocky soil and as a ruderal plant, on plains and uplands up to 1000m above sea level (Hallier 1887; Hegi 1929; Bremer 1994).