The furanocoumarins, or furocoumarins, are a class of organic chemical compounds produced by a variety of plants. Most of the plant species found to contain furanocoumarins belong to a handful of plant families. The families Apiaceae and Rutaceae include the largest numbers of plant species that contain furanocoumarins. The families Moraceae and Fabaceae include a few widely distributed plant species that contain furanocoumarins.[1]
Generally furanocoumarins are most abundant in plants that have flowered and in ripe seeds and fruits.[1] (An exception is the common fig where furanocoumarins are found chiefly in the milky sap of the leaves and shoots but not the fruits.[2]) During the early stages of plant growth, their presence is not easily detected.