One kind. Bitter wheat lettuce is a separate species, there is only one kind, the Chinese literary name is bitter chicory, bitter wheat lettuce grows in the northern arid areas as well as sand dunes or other sandy soils, rich in potassium, sodium, calcium, magnesium, phosphorus, zinc, copper and other elements, there are clearing away heat, resolving stasis and stopping bleeding, swelling and pus as well as inhibiting white blood cells, treatment of eye diseases and other effects.