Filsoniana
Filsoniana is a genus of squamulose lichens in the family Teloschistaceae. It has seven species. Filsoniana is distinguished from Caloplaca by its thallus that contains anthraquinones, in the tissue structure comprising the rim of the apothecia, and in differences in the cortical layer on the underside of the.
Taxonomy
Filsoniana was circumscribed in 2013 by Ingvar Kärnefelt, Arne Thell, Jae-Seoun Hur, Sergey Kondratyuk, and John Elix following a molecular phylogenetic analysis of the Teloschistaceae. The generic name honours the Australian lichenologist Rex Bertram Filson, "in recognition of his contribution to lichenology, in particular to the lichen flora of Australia".Description
Genus Filsoniana is characterised by its distinctive pinkish to brownish-pink body that grows in either lobed or scale-like patterns. The outer protective layer of the lichen is made up of tightly packed, column-like cells arranged in a distinctive cellular pattern.One of the most notable features of Filsoniana are its reproductive structures, which can range from cup-shaped to partially enclosed. These structures are bordered by tissue that matches the main body of the lichen and contains a similar cellular arrangement. Inside these reproductive structures, each spore-producing sac typically contains eight spores, though usually only 4–6 develop fully. The spores themselves have two compartments with concentrated contents at opposite ends. The lichen also produces small, rod-shaped reproductive cells called conidia.
When tested with potassium hydroxide solution, both the thallus and apothecia turn purple, indicating the presence of anthraquinone compounds, specifically those related to the chemical parietin. This characteristic, along with its lobed or scaly growth form and distinctive cellular structure, distinguishes Filsoniana from the related genus Caloplaca. Additionally, genetic analysis places Filsoniana in a distinct group within the larger family Teloschistaceae.