Niesslia robusta, a new lichenicolous fungus on Tephromela grumosa from Tuscany, Italy
The lichenicolous fungus Niesslia robusta is described as new. It is an aggressive parasite occurring on thalli of Tephromela grumosa, which become bleached and necrotic. It is known from two localities of Mt. Amiata (Tuscany), where it is not rare. The relationship of Niesslia with Nitschkiopsis is briefly discussed, and the new combination Niesslia stictarum is proposed.