No abstract

The Caloplaca saxicola group is the main group of saxicolous, lobed-effigurate species within genus Caloplaca (Teloschistaceae, lichen-forming Ascomycota). A recent monographic revision by the first author detected a wide range of morphological variation. To confront the phenotypically based circumscription of these taxa and to resolve their relationships morphological and ITS rDNA data were obtained for 56 individuals representing eight Caloplaca species belonging to the C. saxicola group. We tested the monophyly of these eight morphospecies by performing maximum parsimony, maximum likelihood and two different types of Bayesian analyses (with and without a priori alignments). Restricting phylogenetic analyses to unambiguously aligned portions of ITS was sufficient to resolve, with high bootstrap support, five of the eight previously recognized species within the C. saxicola group. However, phylogenetic resolution of all or most of the eight species currently included as two distinct subgroups within the C. saxicola group was possible only by combining morphological characters and signal from ambiguously aligned regions with the unambiguously aligned ITS sites or when the entire ITS1 and 2 regions were not aligned a priori and included as an integral component of a Bayesian analysis (BAli-Phy). The C. arnoldii subgroup includes C. arnoldii, comprising four subspecies, and the C. saxicola subgroup encompasses seven species. Contrary to the C. saxicola subgroup, monophyly of taxa included within the C. arnoldii subgroup and their relationships could not be resolved with combined ITS and morphological data. Unequivocal morphological synapomorphies for all species except C. arnoldii and C. pusilla are recognized and presented.

The new species Lepraria santosii Argüello & Crespo is described from the Canary Islands. It is characterized by a crustose to subsquamulose thallus with slightly raised rim and the presence of atranorin and the stictic acid chemosyndrome. It is currently known from Tenerife (Canary Islands), where it grows on soil over basaltic rocks in the laurel forest. Twelve new sequences of the ITS region from this species and L. isidiata were obtained and analysed with sequences downloaded from GenBank. Maximum parsimony and Bayesian analyses suggest that Lepraria santosii is closely related to L. isidiata. The latter name is here lectotypified and the characters for the distinction of the two species from similar taxa are discussed.

The genus Diploschistes includes crustose lichen–forming fungi with a carbonized proper excipulum with lateral paraphyses, and a chemistry dominated by orcinol depsides. However, the taxon D. ocellatus lacks these excipular characters and has β–orcinol depsidones, raising doubts about its inclusion within this genus. Using a two–locus dataset (mtSSU, nuLSU), our phylogenetic analyses confirm the classification of D. ocellatus within Diploschistes. Three different groups have been recognized within this genus, based on ascomatal morphology: Actinostomus (perithecioid), Scruposus (urceolate), and Ocel latus (lecanoroid). These groups have been widely used in monographic studies and keys, but their taxonomic value has not been confirmed yet. Here we inferred phylogenetic relationships within Diploschistes, with a special emphasis on the D. scruposus complex, using a combined dataset consisting of morphological, chemical, nrITS, and mtSSU data in order to determine if these species groups and phenotypically based species delimitations were monophyletic. Based on our results, a new subgeneric treatment for Diploschistes is proposed, and the taxonomic value of fruiting body types is confirmed. The clade corresponding to D. ocellatus consists of two well–supported subclades, one of them grouping specimens without ascomata, having only pycnidia. It is also remarkable that the clade containing specimens of D. diacapsis subsp. neutrophilus appears distantly related to the clade containing all other accessions of D. diacapsis. Our analysis revealed that for some taxa, such as D. scruposus and D. interpediens, molecular variability did not correlate with either morphological or chemical diversity.

The position of the sterile western Mediterranean crustose-placodioid lichen generally known as Lecanora lisbonenesis has been investigated using mitochondrial SSU rDNA sequence data. It proves to belong to an independent genus of Physciaceae, for which the generic name Coscinocladium is available, and the earliest species name is Variolaria gaditana. Previous reports of apothecia in the species prove to be a result of mixtures with other lichen species. A lectotype is selected for L. lisbonensis, a neotype designated for V. gaditana, and the new combination Coscinocladium gaditanum made. The species is described, illustrated, its ecology discussed, and a distribution map provided. Fig. 1. Coscinocladium gaditanum (MAF 9855 -neotype). Crespo & al. • Coscinocladium, an overlooked lichen genus 53 (2) • May 2004: 405-414 408 Fig. 3. Mitochondrial SSU rDNA majority-rule consensus tree based on 9600 trees from a B/MCMC tree sampling procedure. Posterior probabilities equal to or above 95 are given above the branches. Buellia groupPhyscia group cal conidia he measured as 3.8-5 × 1.3 µm. These structures are very similar to those known in Physcia and Physconia (Vobis, 1980), and consistent with the relationships that emerged from our molecular studies.