Usnea Dill. ex Adans.
Index Fungorum number: IF 5692; Mycobank number: MB 5692
Notes – The genus Usnea forms a strong supported clade (named “usneoid”) within the phylogeny of Parmeliaceae (Crespo et al. 2007) sister to Cornicularia normoerica (Divakar et al. 2015). Usnea is a fruticose lichen genus easily recognized by its thallus branches with radial symetry, the presence of a central cartilaginous axis and the production of usnic acid in the cortex. The first major work about the genus Usnea was published by Motyka (1936), who published more than 750 names in his world monograph, many of them are now considered synonyms of well-known species (Clerc 1998). Usnea is among the ten richest genus among the lichenized fungi in number of species with 350 species (Lücking et al. 2016), but actually molecular phylogeny indicated that the number could be twice (Lücking et al. 2020). Modern revisions of the genus were done in Africa (e.g., Temu et al. 2019), Australia (e.g., Stevens 2004), Europe (e.g., Clerc and Otte 2018), India (e.g., Shukla et al. 2014), Japan, China and Russia (e.g., Ohmura 2001; Ohmura et al. 2017), New Zealand (e.g., Galloway 2007), North America (e.g. Herrera-Campos 2016), South America (e.g. Gerlach et al. 2020), and Polar regions (e.g. Wirtz et al. 2012).
Species