This association is usually dominated by two species, Lactuca serriola, occurring in the upper layer, and Conyza canadensis in the lower layer. Monodominant stands of one of these two species are also common. They occur on warm and sunny sites with shallow, dry, sandy to stony, nutrient-poor soils. They are typical of initial stages of secondary succession, and are soon replaced by other vegetation types with perennial species. This type is common in lowland and colline areas of the Czech Republic, but also occurs in slightly cooler areas.