Dandelion coffee In 1919, dandelion root was noted as a source of cheap 'coffee'. It has also been part of edible plant classes dating back at least to the 1970s. Harvesting dandelion roots requires differentiating 'true' dandelions ("Taraxacum" spp.) from other yellow daisy-like flowers such as catsear and hawksbeard. True dandelions have a ground-level rosette of deep-toothed leaves and hollow straw-like stems. Large plants that are 3–4 years old, with taproots approximately 0.5 inch (13 mm) in diameter, are harvested for dandelion coffee. These taproots are similar in appearance to pale carrots. After harvesting, the dandelion roots are dried, chopped, and roasted.
Plant to plant communication via mycorrhizal networks they can down regulate defense genes, affect mitochondrial function, and disrupt membrane permeability leading to issues with respiration. Plants produce many types of allelochemicals, such as thiopenes and juglone, which can be volatilized or exuded by the roots into the rhizosphere. Plants release allelochemicals due to biotic and abiotic stresses in their environment and often release them in conjunction with defensive compounds. In order for allelochemicals to have a detrimental effect on a target plant, they must exist in high enough concentrations to be toxic, but, much like animal pheromones, allelochemicals are released in very small amounts and rely on