<i>Aurantiothallia</i> and <i>Hertelaria</i> , two new genera of porpidioid <i>Lecideaceae</i> ( <i>Ascomycota, Lecanoromycetidae, Lecideales</i> ), and other new porpidioid taxa from Tasmania

Abstract The new genera Aurantiothallia and Hertelaria are proposed for species of saxicolous lichens known only from Tasmania. Aurantiothallia is erected for the species currently known as Poeltiaria tasmanica and the newly described A. riparia , both of which have an orange thallus lacking lichen products but with an amyloid medulla and black apothecia with only brown pigments internally. Hertelaria is based on the new species H. doleritica , which has an atrobrunnea-type thallus and large adnate, red-brown apothecia up to 2.4 mm diam. Phylogenetic analyses based on the markers ITS, mtSSU and RPB 1 clearly support the morphological results, each genus forming a strongly supported clade. Also newly described are: Poeltiaria caeruleorubra , with a red-pigmented inner exciple that contrasts strongly with the adjacent bright blue hymenium; Porpidia lutulata , which has small apothecia and a granular thallus with an amyloid (I+ violet) medulla; and Porpidia umbonifera var. sanguinea , which differs from the typical variety in having a reddish pigment in the inner exciple. All the new taxa are known only from silicious rocks, mostly dolerite, in Tasmania. We also report Porpidia albocaerulescens var. polycarpiza and P. hydrophila for the first time from Tasmania, confirm the presence of P. umbonifera var. umbonifera on the island, and provide a provisional key to porpidioid lichens in Tasmania.