The Estonian Mycological Collections of Heinrich August Dietrich (1820–1897)

Heinrich August Dietrich was a gardener with a deep interest in mycology. He published a two-volume monograph dealing with over 1,000 fungal and fungal-like taxa, the first cryptogamic research of this kind for the Baltic region. Between 1852 and 1857, H. A. Dietrich issued nine volumes of exciccatae named Centuria Plantarum Florae Balticae cryptogamarum. The preserved eight Centuriae and additional collections from Estonia (then the Imperial Russian Baltic province, Estonian Governorate) are revised and their current status in collections is presented. As a result, a new myxomycete species for Estonia, Physarum gyrosum, and the once doubtfully-reported species, Arcyria oerstedii, are recorded, and the earliest vouchers of some endangered ascomycetes, such as Poronia punctata and Sabuloglossum arenarium, are identified in his material. The most remarkable findings among lichenized fungi are Alectoria sarmentosa, Dibaeis baeomyces, Flavoparmelia caperata, Lasallia pustulata, Nephroma laevigatum, Peltigera venosa and Ramalina calicaris, as well as the oldest Estonian specimen of Lobaria pulmonaria.