Sanguineodiscus I.V. Frolov & Vondrák, gen. nov. Fig. 3C

Index Fungorum number: MB 828647; Facesoffungi number: FoF

Etymology: Included lichens often have deep red (sanguineous) apothecial discs.

Type: Sanguineodiscus viridirufus (Ach.) I.V. Frolov & Vondrák

Diagnosis: Apothecial disc pale to dark red with anthraquinones of the chemosyndrome A (sensu Søchting, 1997), exceptionally lacking anthraquinones and brown or black (Fig. 3C, right). True exciple often grey-black or the same color as disc. Thallus and thalline exciple with Sedifolia-grey, lacking anthraquinones. Distributed in Eurasia and Northern Africa, mainly in the Mediterranean basin and Central Asia. Saxicolous and corticolous.

Description: Morphology and anatomy: Thallus crustose, epilithic or epiphytic, white to dark grey; cortex paraplectenchymatous, well developed in lower part of thalline exciple, but only alveolate cortex (sensu Vondrák et al., 2013) developed in thallus; vegetative propagules not known. Apothecia zeorine, sometimes seemingly lecanorine, but thin true exciple is always present. Disc dark to pale red, but rarer some individuals have black or brown discs without anthraquinones (Fig. 3C, right). True exciple orange to red, but its outer rim often grey, darker than thallus and thalline margin. Thalline exciple of the same colour as thallus. Ascospores polardiblastic,ellipsoid, with medium to large long septum; pycnidia often present, grey-black; conidia bacilliform.

Chemistry: Thallus and thalline exciple always without anthraquinones, usually with Sedifolia-grey. Epihymenium and inner rim of true exciple usually with anthraquinones. Outer rim of true exciple may contain only anthraquinones or both anthraquinones and Sedifolia-grey. Rare chemotypes with black colored apothecia (without anthraquinones, only with Sedifolia-grey) are occasionally recorded within typical populations (Fig. 3C, right).

Distribution and ecology: Distributed in Europe, Northern Africa and Asia, but main occurrence is in the Mediterranean basin and Central Asia. Saxicolous or corticolous. Saxicolous taxa occur on inland rain-sheltered base-rich siliceous rocks (S. viridirufus), seashore siliceous rocks (S. aractinus) in western Eurasia or on calcareous outcrops in Central Asia (S. bicolor). Corticolous species grow on deciduous and coniferous trees and shrubs predominantly in Mediterranean regions and Macaronesia. Remarks: Currently four species are included in the genus, but this group is more diverse and contains unnamed taxa (both saxicolous and corticolous; Vondrák, unpublished).

Fig. 3. Representatives of the genera in Pyrenodesmia sensu lato (A–C), and the species indicated to be outside Pyrenodesmia sensu lato (D–F). A, Pyrenodesmia chalybaea (PRA Vondrák 9686). B, Kuettlingeria teicholyta (holotype of Blastenia visianica, VER, photo by U. Arup). C, Sanguineodiscus aractinus, thallus with red apothecia with anthraquinones on the left and thallus with black anthraquinone-lacking apothecia on the right (PRA Vondrák 9600). D, Caloplaca obscurella (PRA Vondrák7641). E, Caloplaca reptans (NY Lendemer 48186). F, Caloplaca demissa (PRA Vondrák19188). All scales: 1 mm.