Rufoplaca
Rufoplaca is a genus of lichen-forming fungi in the family Teloschistaceae. The genus is found primarily across the Northern Hemisphere, with most species occurring in Europe and additional records from North America and Asia. These lichens typically grow as thin crusts with orange-red colouration on sun-exposed rocks and other surfaces. The genus was established in 2013 to group together several previously scattered species that genetic studies showed formed a natural evolutionary lineage.
Taxonomy
Rufoplaca was established by Ulf Arup, Ulrik Søchting and Patrik Frödén to accommodate a coherent set of orange-red Teloschistaceae previously scattered in other genera; the type species is Rufoplaca subpallida. The name means, referring to the colour of the fruiting bodies. In their analyses, the genus formed a fairly uniform lineage; its closest relative was Usnochroma, which differs chemically and in spore form. Species of Rufoplaca can resemble Blastenia in general appearance, but Rufoplaca characteristically has orange-to-rusty apothecia rich in chlorinated anthraquinone pigments. Taxa of the former "Caloplaca xerica" species group are also similar; however, they differ in their chemistry, showing a different pigment suite. The circumscription originally included the following new combinations: R. arenaria, R. germanica, R. oxfordensis, R. scotoplaca, R. subpallida, and R. tristiuscula.Description
The thallus is crustose, forming a thin, paint-like crust on the substrate, and may range from very thin to relatively thick; in some specimens it can be so reduced as to appear absent. A distinctive grey pigment may be present in the thallus. The apothecia are orange to rusty red and have rims that vary from to in form—that is, the edge may be formed only by the fruit body tissue or may include a thin rim of thallus tissue around it. Asci produce two-celled spores with a short to medium-length septum between the two end chambers, a spore type common in this family. Asexual reproductive structures may be present or absent; when present they produce slender, rod-shaped to narrowly ellipsoid conidia.Chemically, species of Rufoplaca conform mostly to chemosyndrome A, meaning they share a characteristic set of lichen pigments dominated by chlorinated anthraquinones; gyrophoric acid may occur rarely.