sentences:  In particular, the linear furanocoumarins (psoralen, bergapten, and methoxsalen), which occur naturally in Apiaceae, Rutaceae, and other plant families, are known to be toxic to fungi.Plants that cause phytophotodermatitis usually contain linear furanocoumarins.Furanocoumarins are found in the sap of plants such as "Ammi majus", parsnip, and giant hogweed.