Fungi he named include the deadly Lepiota helveola and Inocybe patouillardii, though the latter is now known as Inosperma erubescens as this latter description predated Bresadola's by a year.

During this period, he again started to become keenly interested in botany and spent time with Francesco Ambrosi, who introduced him to the bryologist Gustavo Venturi and the work of Carlo Vittadini.

From this point on, he maintained a voluminous and broad correspondence with upwards of 400 Italian and foreign specialists, a collection that is now housed at the Museo delle Scienze in Trento.

He became a leading specialist in various areas, in which he enjoyed close collaborations: Agaricomycetes, with Quélet and Adalbert Ricken; Aphyllophoromycetideae, with Narcisse Théophile Patouillard and the Canon Hubert Bourdot; and finally Discomycetes with Boudier.

He also developed a keen interest in exotic specimens and published various observations on examples he received from all parts of the world, including Cameroon, Congo, Hungary, Saxony, Poland, San Tomé, and Samoa.

Under the auspices of the Italian Botanical Society and the Natural History Museum in Trent, he undertook the monumental Iconographia mycologica, a partially posthumous work which comprised some 25 volumes and 1,250 colour plates.