The origin of Persoon's botanical interest is unknown. The earliest of his writings was "Abbildungen der Schwämme" (Illustrations of the fungi). It was published in three parts. The first was published in 1790. The second in 1791. The third was published and 1793. Between 1805 and 1807, he published two volumes of his "Synopsis plantarum" . This was a popular work describing 20,000 species of all types of plants. But his pioneering work was in fungi. He wrote several things related to mushrooms and other forms of fungi. Beginning with the "Synopsis methodica fungorum" (1801); it is the starting point for nomenclature of the Uredinales, Ustilaginales, and the Gasteromycetes. In 1815, he was elected a corresponding member of the Royal Swedish Academy of Sciences.