Thelopsis challenges the generic circumscription in the Gyalectaceae and brings new insights to the taxonomy of Ramonia

Abstract

The genus Thelopsis was classified in the family Stictidaceae but its systematic position has never been investigated by molecular methods. In order to determine its family placement and to test its monophyly, fungal DNA of recent collections of Thelopsis specimens was sequenced. Phylogenetic analyses using nuLSU, RPB2 and mtSSU sequences reveal that members of Thelopsis form a monophyletic group within the genus Gyalecta as currently accepted. The placement of Thelopsis, including the generic type T. rubella, within the genus Gyalecta challenges the generic circumscription of this group because Thelopsis is well recognized by the combination of morphological characters: perithecioid ascomata, well-developed periphysoids, polysporous asci and small, few-septate ellipsoid-oblong ascospores. The sterile sorediate Opegrapha corticola is also placed in the Gyalectaceae as sister species to Thelopsis byssoidea + T. rubella. Ascomata of O. corticola are illustrated for the first time and support its placement in the genus Thelopsis. The hypothesis that O. corticola might represent the sorediate fertile morph of T. rubella is not confirmed because the species is phylogenetically and morphologically distinct. Thelopsis is recovered as polyphyletic, with T. melathelia being placed as sister species to Ramonia. The new combinations Thelopsis corticola (Coppins & P. James) Sanderson & Ertz comb. nov. and Ramonia melathelia (Nyl.) Ertz comb. nov. are introduced and a new species of Gyalecta, G. amsterdamensis Ertz, is described from Amsterdam and Saint-Paul Islands, characterized by a sterile thallus with discrete soralia. Petractis luetkemuelleri and P. nodispora are accommodated in the new genus Neopetractis, differing from the generic type (P. clausa) by having a different phylogenetic position and a different photobiont. Francisrosea bicolor Ertz & Sanderson gen. & sp. nov. is described for a sterile sorediate lichen somewhat similar to Opegrapha corticola but having an isolated phylogenetic position as sister to a clade including Gyalidea praetermissa and the genera Neopetractis and Ramonia. Gyalecta farlowii, G. nidarosiensis and G. carneola are placed in a molecular phylogeny for the first time. The taxonomic significance of morphological characters in Gyalectaceae is discussed.

Unravelling the diversity of the lichen genus Porina (Porinaceae) in Mauritius

“…species formerly placed in the genus Crocynia but now subsumed within Phyllopsora (Kistenich et al 2018), Lecanactis mollis (Stirt.) Frisch & Ertz in the Roccellaceae (Ertz et al 2015), and Thelopsis byssoidea Diederich in the Gyalectaceae (Aptroot et al 1997;Ertz et al 2021). A byssoid thallus is considered to be an adaptation to constantly humid climatic conditions characteristic of a tropical forest understory (Lakatos et al 2006;Nelsen et al 2010).…”

A New Corticolous Species of Mazosia A.Massal. (Roccellaceae, Arthoniales) from Guadeloupe, Remarkable by its Byssoid Thallus

“…Hafellner & Vězda 1992; Harris 1995; Kistenich et al 2018; Ertz & Diederich 2022) and Gyalectales (e.g. Aptroot et al 1997; Ertz et al 2021). Within the Arthoniales, parallel evolution of byssoid thalli occurred in the families Arthoniaceae and the Roccellaceae and is usually considered as a synapomorphy of some generic level lineages like Crypthonia Frisch & G.Thor, Dichosporidium , Herpothallon Tobler and Sagenidiopsis .…”

Morphological and Phylogenetic Appraisal of Novel and Extant Taxa of Stictidaceae from Northern Thailand

“…The remaining 22 genera, including Absconditella , Acarosporina , Carestiella , Cryptodiscus , Cyanodermella , Eriospora , Fitzroyomyces , Geisleria , Glomerobolus , Hormodochis , Ingvariella , Neofitzroyomyces , Neostictis , Ostropa , Ostropomyces , Phacidiella , Robergea , Schizoxylon , Sphaeropezia , Stictis , Trinathotrema and Xyloschistes , have been confirmed as members of Stictidaceae by phylogenetic methods. Thelopsis historically has been assigned to Stictidaceae, however, recent phylogenetic analyses of combined LSU, mtSSU and RPB2 sequences have placed this genus outside this family, with the type species placing within Gyalecta (Gyalectaceae) [ 21 ]. Stictidaceae currently comprises 32 genera, including 19 sexual (in orange area, Figure 1 ), five asexual genera (in purple area) and seven genera for which both morphs have been observed (in blue area).…”