Lichens from the Colombian Amazon: 666 Taxa Including 28 new Species and 157 New Country Records Document an Extraordinary Diversity

Abstract. In this study, we revised the lichen collection at the Herbario Amazonico Colombiano (coah) in Bogotá, Colombia. The collection has a total of nearly 2,400 specimens, with some duplicates in the Herbario Nacional (col) and in the herbarium of the Botanic Garden in Berlin (b). The revision of 1,861 specimens revealed 574 species in 142 genera and 44 families, among which there are 28 species new to science and seven new combinations. Previously, 324 species had been reported from the Colombian Amazon, and our revision resulted in a new total of 666 species, more than doubling the previous number. All 666 species are enumerated here in the first comprehensive checklist of lichens from the Colombian Amazon. A total of 157 new country records (53 already reported in the new Catalogue of Fungi of Colombia) increase the number of lichens known from Colombia to 2,827. The following species are described as new: Allographa exuens, differing from A. argentata by the lirellae with the corticiform layer soon flaking off and exposing the black labia, the only finely inspersed hymenium, and the narrower ascospores; A. guainiae, differing from Graphis syzygii in the prominent ascomata with lateral thalline margin and whitish thallus remnants between the striae; A. labiata, differing from A. immersa in the prominent lirellae with conspicuous, entire, exposed labia, an inspersed hymenium, longer ascospores, and stictic acid as secondary compound; A. lichexanthonica, differing from A. sitiana in producing lichexanthone; A. sessilis, differing from A. contortuplicata in the muriform ascospores; A. suprainspersata, differing from A. angustata in the very thin thalline cover of the ascomata and the apically inspersed hymenium; Astrothelium bireagens, differing from A. cinnamomeum by the broader, apically flattened perithecia covered by a thin, ferruginous-red, K+ deep purple pruina and internally with an ochraceous-yellow, K+ deep yellow pigment; A. stromatolucidum, differing from A. neovariolosum in the distinctly pseudostromatic ascomata; Carbacanthographis submultiseptata, differing from C. multiseptata in the narrower ascospores and the indistinct periphysoids; Chapsa inconspicua, differing from C. angustispora in the smooth to uneven versus farinose thallus and in the much shorter ascospores; Coenogonium velutinellum, differing from C. pineti in the finely velvety, rather thick thallus composed of irregular to erect, densely packed algal threads covered by a thin pseudocortex; Fellhanera naevioides, differing from F. naevia in the finely dispersed, minutely crenulate thallus and the blackish apothecia; Fissurina sipmanii, differing from F. amazonica in the shorter and broader, slightly gaping, somewhat chroodiscoid ascomata, and the amyloid ascospores; Glyphis lirellizans, differing from Glyphis substriatula in the erumpent vs. prominent lirellae with lateral thalline margin and the exposed disc; Graphis papillifera, differing from G. stellata in the lirellae lacking a thalline margin, very elongate and irregularly to radiately branched and not in stellate clusters, and in the 5-septate ascospores; G. pseudoglyphis, differing from Graphis stellata in the non-verrucose thallus, the branched lirellae which do not, however, form stellate clusters, and the shorter ascospores; Malmidea flavimarginata, differing from M. bacidinoides in the pale yellow, K+ deep yellow medulla and yellow, K+ deep yellow excipular crystals, as well as the smaller ascospores; M. isidiopiperina, differing from M. taytayensis in the smaller ascospores; M. papillitrailiana, differing from M. trailiana in the papillose apothecial margins; Myriotrema araracuarense, differing from Myriotrema muluense in the non-annulate pores of the apothecia and in the longer ascospores; Ocellularia areolata, differing from Ocellularia rhicnoporoides in the pigmented medulla and the larger, more prominent apothecia with completely carbonized excipulum; O. caquetensis, differing from Ocellularia rotundifumosa in the absence of a columella; O. inspersipallens, differing from O. viridipallens in the inspersed hymenium and the 5–7-septate ascospores; O. rufocinctoides, differing from O. rufocincta in the thallus lacking large and irregular crystal clusters, in the more prominent apothecia and in the smaller ascospores; O. sipmanii, differing from Ocellularia abbayesiana in the smaller, 3-septate ascospores; Pseudopyrenula daironii, differing from all other species of the genus in the aggregate perithecia with shared ostiole and the internal orange-red pigment granules lining the perithecial wall; Pyrenula asymmetrica, differing from Pyrenula papilligera in the longer, almost rectangular ascospores; and Redingeria pseudostromatica, differing from other species in the genus in the pseudostromatic ascomata with small, rounded apothecia, in combination with 1-septate ascospores. In addition, the following seven new combinations are proposed: Bacidina cyanophila (≡ Bacidina simplex var. cyanophila), Malmidea sorediifera (≡ Lecanora sorediifera), Ocellularia fuscescens (≡ Thelotrema fuscescens), Phaeographis cymbegrapha (≡ Graphis cymbegrapha; = Phaeographis amazonica Staiger], Polyblastidium flavosquamosum (≡ Heterodermia flavosquamosa), Polyblastidium lamelligerum (≡ Parmelia lamelligera), and Polyblastidium rottboellii (≡ Anaptychia hypoleuca var. rottboellii).