Please note that the content of this book mainly consists of articles that are available online from Wikipedia or other free sources. Weeds are plants of spontaneous accompanying vegetation in cultivated crops, grasslands, or garden areas that are not intentionally grown there and come from the soil's seed potential or through natural dispersal. In common language, the main criterion for labeling a plant as a weed is that it is undesirable. Depending on the perspective of the affected party, an already incurred or feared economic damage or an aesthetic reason can trigger the feeling of disturbance. This can involve unwanted wild plants or spontaneously growing cultivated plants.