given priority even if the normal nomenclatural rules would give precedence to another nameand indeed the Danish mycologist Heinrich Christian Friedrich Schumacher had already described the same species as Agaricus gracilis in 1803. The sanctioning can be shown in the author string by means of a colon as in the following: "A. porphyria Alb. & Schwein. : Fr." The epithet porphyria comes from the Ancient Greek word porphúra (πορφύρα), meaning the Tyrian purple dye. This colour may be seen in the cap of the mushroom (though it is not always evident). See also List of Amanita species References Further reading E. Garnweidner. Mushrooms and Toadstools of Britain and Europe. Collins. 1994. External links porphyria Poisonous fungi Fungi of North America Fungi of Europe Taxa named by Lewis David de Schweinitz Taxa named by Johannes Baptista von Albertini