Refining the picture: new records to the lichen biota of Italy

Abstract Based on the analysis of both historical and recent collections, this paper reports an annotated list of taxa which are new to the lichen biota of Italy or of its administrative regions. Specimens were identified using a dissecting and a compound microscope; routine chemical spot tests and standardized thin-layer chromatography (TLC or HPTLC). The list includes 225 records of 153 taxa. Twenty taxa are new to Italy, the others are new to one or more administrative regions, with 15 second records and 5 third records for Italy. Some of the species belong to recently-described taxa, others are poorly known, sterile or ephemeral lichens which were largely overlooked in Italy. Several species are actually rare, either because of the rarity of their habitats (e.g. old-growth forests), or because in Italy they are at the margins of their bioclimatic distribution. The picture of the lichen biota of Italy has now new pixels, but its grain is still coarse. Further analysis of historical collections, increased efforts in the exploration of some areas, and the taxonomic revision of critical groups are still necessary to provide more complete distributional data for new biogeographic hypotheses, taxonomic and ecological research, and biodiversity conservation.


Introduction
The lichen biota of Italy is among the best known worldwide thanks to a long-lasting tradition of lichenological studies (Nimis 2018) that has experienced a strong boost after the publication of the first modern checklists (Nimis 1993(Nimis , 2016, and of the first computer-aided keys . This is reflected in the steep increase of the number of species known to occur in Italy, more than 550 species having been added between 1993 and 2016 (Nimis 2016). Since 2016, new records (both for the country and for its administrative regions) are constantly being published every year (e.g. Ravera et al. 2020aRavera et al. , b, 2021, which indicates that the exploration of the lichen biota of Italy is still incomplete, and that distributional data of many species are still lacunose (e.g. Martellos et al. 2020). More information is available for the regions of the North, Tuscany and Sardinia (Nimis 2016), all of which are known to host more than 1.000 species each, while most regions of Southern and Central Italy are still insufficiently explored, which may hamper accurate estimations of species rarity (Nimis et al. 2018a), analyses of species richness and composition patterns (Marini et al. 2011), as well as species distribution models (Guttová et al. 2019).
In this work we report the results of the analysis of recent collections and the reevaluation of herbarium specimens, mainly collected during the last twenty years, in the light of recent taxonomical progress. Twenty taxa are new to Italy, 133 are new to different administrative regions, thus providing a substantial contribution to the knowledge of the lichen biota of Italy.

Materials and methods
Based on the analysis of herbarium material (BOLO, GZU, M, MOD, TSB, RO, UPS, Herb. Nascimbene and other private herbaria), an annotated list of taxa which are new to the lichen biota of Italy or of its administrative regions, has been prepared. The specimens were identified in the laboratory using a dissecting and a compound microscope. Routine chemical spot tests were performed for most specimens. In some cases (i.e. for sterile crustose lichens) standardized thin-layer chromatography (TLC) was used, following the protocols of Orange (2010), or HPTLC, following Arup et al. (1993).
Nomenclature, as well as synonimization of old records, mainly follow ITALIC 6.0 -The information system on Italian Lichens (Nimis and Martellos 2021), which is continuously updated online. This source was used also for retrieving ecological and distributional information for each taxon.
Taxa are subdivided in two alphabetically ordered lists: 1) new to Italy, 2) new to administrative regions of Italy (see Fig. 1). For each taxon, the following information is included: 1. administrative region; 2. collection locality, elevation, and substrate. When available, longitude and latitude are reported in DMS. Coordinates available on the original label of the specimens in other formats were converted to this system; 3. collection date, collector(s) name (Leg.), and Herbarium code. Institutional herbaria are abbreviated according to Index Herbariorum (Thiers 2016). The private herbarium of J. Nascimbene is abbreviated as Herb. Na; 4. short note on ecology, distribution and/or taxonomy.  44°26'49"N, 11°22'45"E; 195 m; 07 May 2021; Nascimbene leg.; on terricolous bryophytes above gypsum; Na 7230.

Taxa new to Italy
An almost cosmopolitan species of dry areas, found on calciferous soil in dry grasslands, which can be easily mistaken for E. tenax. It might be more widespread in Italy, especially in dry Mediterranean areas of the South. A rare European species with a boreal to temperate-high montane distribution, found on branches of various trees and shrubs near the ground, but also on rocks in very humid places, like in the spray zone of waterfalls. Our specimen was found on bark of Salix caprea in a very humid old-growth spruce forest, together with other suboceanic cyanolichens (e.g. Pannaria conoplea, Peltigera collina, Nephroma parile).
When sterile, as in the case of our collection, the species is recognised by the thallus which consists of a thin film interrupted by patches of concave goniocystangia (van den Boom and Vězda 2000). Described from Switzerland, but widely distributed in Europe, North America and Asia. This inconspicuous species settles in a narrow ecological niche, growing on the upper parts of moribund Polytrichum-gametophytes, in the Alps only at high altitudes. For a detailed treatment see Obermayer and Poelt (1994). A species with an epilithic thallus consisting of pale grey to pale brown areolate to subsquamulose areoles, and 1-2 mm wide apothecia with brown, somewhat raised discs; usually on acidic schistose rocks .
The species is recognised by its flat, hardly protruding, orange apothecia dispersed on a whitish to cream-coloured semi-endolithic thallus. It grows on steep, shaded faces of limestone. For a detailed treatment see Hafellner (2006).
An arctic to nemoral-alpine species morphologically resembling R. norvegicum, but ascospores submuriform, larger (to 20 µm long), with 1-4 transverse septa and 1 incomplete longitudinal septum. It colonises basic siliceous rocks and schists with low content of calcium in exposed situations, and starts the life-cycle on various crustose lichens. Most records from the Alps are in the central-eastern part (Nimis et al. 2018a), but the species is likely to have been overlooked in some regions.
This species, described from the Western Alps (France), is found on periodically moist calcareous rocks, e.g. along streams at high elevations, or in shaded-humid situations. Our specimen was collected on dolomite washed by melting water in the nival belt.
A critical taxon, hitherto known only from the type locality in Switzerland where it was collected on calcareous rocks in upland areas. Similar to other Thelidium-species, this taxon would require further research to clarify its taxonomic position. Our specimen was collected in a very humid wall of the early Triassic Werfen-formation composed of carbonatic, terrigenous and mixed, varicolored deposits that are sometimes dolomitized. The ecological conditions of the site are similar to those of the type locality, where the species was found together with Polyblastia cupularis, as in our case.
This species is widespread in the Alps (Nimis et al. 2018a) on inclined surfaces of compact calciferous rocks in rather shaded, non-eutrophicated situations near or above treeline. Since it was not always distinguished from similar species, it has an apparently incomplete distribution in the Alps. This is an obligately sterile species with a thallus consisting of scattered, whitish, adnate areoles and usually marginal soralia, containing alectorialic acid and therefore turning reddish with age. It is widespread in the Holarctic region from the boreal to the nemoralmontane zone, including the Alps (most records being from the eastern part), but was still largely overlooked in Italy, where it may be more widespread, at least in the Alps. Probably overlooked and more widespread, both in the Alps and in the Apennines, with optimum near and above treeline, this lichen starts the life-cycle on species of Aspicilia, especially A. candida and A. polychroma, on calciferous rocks which are at least partly decalcified on the surface.
A probably holarctic species of base-rich, weakly calciferous siliceous substrata, such as calcareous sandstone, brick, and roofing tiles, usually at relatively low elevations; much overlooked or confused with other species and certainly more widespread in Italy. On hard calcareous rocks, both on vertical faces and at the top of birds' perching sites in dry-continental areas, below the subalpine belt.
The only previous record of this lignicolous species from Italy is that of a specimen collected on a horizontal wood fence in a vineyard near Merano, at c. 500 m (Nimis 2016). Our sample was collected on a similar substrate but at higher elevation, indicating that in Italy this species could span a wide altitudinal range.
A rare lichen usually growing on pertusarioid silicicolous species, mainly Tyrrhenian in Italy. Our specimen was collected in old-growth Castanea-stand near Bologna (Pezzi et al. 2020 An arctic-alpine to boreal-montane, probably circumpolar species found amongst mosses and moribund plants on base-rich siliceous substrata in the alpine and subalpine belts.
Apparently widespread in Central Europe, but poorly collected elsewhere, growing on steeply inclined, sunny surfaces of calcareous or basic siliceous rocks with periodical water seepage after rain.
An early coloniser on exposed calcareous rocks below the subalpine belt; overlooked and probably more common, especially in the EU-Mediterranean belt. It also occurs in warm-dry Alpine valleys. A mild-temperate lichen found near the base of old trees, mostly on rough bark, especially of Quercus sp., more rarely on wood, in very humid and closed-canopied forests. Included in the Italian red list of epiphytic lichens as "Near-threatened" (Nascimbene et al. 2013 On weakly calciferous rocks, mostly near or above treeline. Our samples were collected on the selciferous carbonatic rock of the late Jurassic formation called "Formazione di Fonzaso".
A chemically variable species found on siliceous rocks, sometimes also on pebbles, widespread in the Alps (Nimis et al. 2018a), but very much overlooked in Italy. A species with grey thalli showing somewhat effigurate margins, the central parts covered in short, thick, hollow papillate structures gradually breaking down into flattened propagules (Poelt 1994). It is restricted to subvertical to overhanging faces of siliceous cliffs from treeline to the nival belt. At the investigated site several thalli have been found, colonised by parasitic Lecidea tessellata. A mild-temperate to humid subtropical species, most common on pebbles over moist ground in areas with siliceous substrata; certainly overlooked and probably more widespread in Tyrrhenian Italy, with outposts in the Alps. On siliceous rocks in open lichen communities near or above treeline (i.e. near glaciers). Known from Trentino-Alto Adige (Nimis 2016) and probably more widespread in the Alps, but overlooked, being mostly sterile.
A recently-described species of siliceous rocks in the Mediterranean mountains. The record from Calabria (Aspromonte) was cited by Nimis (1993: 167)  A recently described species growing on acid bark, mostly of conifers, or on the branches of shrubs in the subalpine belt. Most previous records of B. herbidella from the Alps (see Nimis 1993Nimis , 2016) could refer to this species, which is probably widespread throughout the Alps. A recently-described species growing on base-rich siliceous rocks in the southern and Central European mountains, mostly above or near treeline. Several earlier records of B. crenularia (see Nimis 1993Nimis , 2016 from alpine-subalpine situations probably refer to this species. A holarctic, temperate species found on bark, rarely on wood of deciduous trees, especially Quercus sp., often in fissures of the bark, more rarely on conifers.
A well-distinct taxon of the critical C. saxicola-complex, found on steeply inclined surfaces of calciferous rocks (limestone, dolomite, calcareous schists) in open habitats; certainly more widespread in Italy. For further details see Gaya et al. (2001). A species with an Alpine distribution, growing mainly on the top of calcareous boulders in sunny and nutrient-enriched sites, often with C. biatorina and Rusavskia elegans. The Italian distribution is poorly known, as the species was frequently confused with C. arnoldii, but probably it is widespread throughout the calcareous Alps, and also occurs in the Central Apennines. All of the Italian records prior to 2008 were under C. arnoldii (see Nimis 2016). The thallus of Caloplaca coccinea is somewhat variable, ranging from entirely immersed and uncoloured to semi-immersed with orange particles. Diagnostic are the semi-immersed to sessile, vivid red apothecia, a colour unique among the alpine caloplacoid lichens. The species, which does not belong to Caloplaca s.str., mostly settles on steeply inclined to vertical rock faces of limestone cliffs and outcrops from the lower alpine to the nival belt.  Roux & Coll. (2014), is not identical with Blastenia subochracea (Wedd.) Arup, Søchting & Frödén. The species, which does not belong to Caloplaca s.str. nor to Blastenia, and whose DNA analysis is pending, has a Mediterranean distribution on compact limestone, being locally very abundant in coastal situations, and extremely rare far from the coast. The colour of the thallus, based on which several infraspecific taxa were distinguished (see e.g. Roux et al. 2014), is variable depending on exposure to sunlight, and intermediate forms are frequent. A new name for the lichen called Xanthocarpia marmorata auct. will be also proposed in a forthcoming paper. A mild-temperate lichen found on old deciduous trees, often near the base of the trunks, often overlooked, or confused with C. cerina (Šoun et al. 2011). It differs from C. monacensis in the well-developed, areolate, rarely fertile thallus with a thick layer of small granules, although molecular data suggest that it could be a sorediate-blastidiate morph of C. monacensis (Vondrák in litt.).
A boreal-montane, poorly understood lichen growing on the top of poles and wooden fences, on plant debris and soil, more rarely on rocks in upland areas; certainly more widespread in the Alps. The delimitation of this species is problematic: most of the material distributed in exsiccata belongs to other species, and it is doubtful whether the material called "C. kuusamoensis" by Central and Southern European authors really corresponds to the type material, which in itself resembles a luxuriant C. vitellina growing on mosses (Westberg, in litt.). A species with the imbricaric acid syndrome (major) and perlatolic acid (minor), mainly found on the bark of broad-leaved trees, more rarely on conifers and silicicolous mosses in humid, old, mostly montane forests; probably the most common species of Cetrelia in Italy.
On decorticated stumps of deciduous and coniferous trees, more rarely on bark and siliceous rocks in old humid forests, on faces slightly protected from rain. Included in the Italian red list of epiphytic lichens as "Endangered" (Nascimbene et al. 2013). This species is included in the Italian red list of epiphytic lichens as "Near-threatened" (Nascimbene et al. 2013 A cool-temperate to boreal-montane, circumpolar lichen found in rain-protected hollows of conifer trunks inside forests, especially near the ground, both on bark and wood. A holarctic species found on acid-barked deciduous trees, conifers and wood in forests and woodlands; widespread in upland areas throughout the country, but most common in the Alps.
This species was collected in the park surrounding an historical building, on the trunk of an old lime-tree that presented some wood areas protected from rain (i.e. dry conditions). The species was probably overlooked in Italy, as indicated by its current scattered distribution pattern across the country. A circumpolar, boreal-subarctic-subalpine lichen, one of the most abundant elements of lichen-rich tundra-like vegetation on mineral soil in exposed habitats. This specimen was likely collected in the summit area of the mountains near Montefortino where altitude exceeds 2000 m. A typical member of subalpine-alpine tundras, perhaps more common at higher altitudes than C. arbuscula. This specimen was probably collected in the same stand of C. mitis (see above). This is the southernmost record for Italy. A temperate, perhaps holarctic early coloniser of basic siliceous rocks and roofing tiles; overlooked, and certainly more widespread in Italy. An apparently widespread but rare, or at least rarely distinguished species, characterised by four-celled spores and a J+ blue medulla .
A mild-temperate lichen starting the life-cycle on species of the Caloplaca teicholytacomplex, the peculiar biology of which deserves further study. It was certainly overlooked in Italy, as indicated by its current scattered distribution pattern across the country. It is similar to D. scheideggerianum that has shorter spores and usually grows on Leproplaca-species. A rare species living as a parasite on Dirina ceratoniae, strictly confined to the Mediterranean belt. Our specimen was collected on isolated trees in an agricultural landscape near the Tyrrhenian coast.
A very inconspicuous species which, on account of its mostly ochraceous to grey thallus and minute black aspicilioid apothecia, is often detected only in screenings of larger collections on limestone pebbles or rock pieces of low outcrops from higher altitudes. Diagnostic are the blue-green epihymenium and asci with a distinct tholus reacting intensely blue with Lugol's reagent, which is the distinguishing character from otherwise similar Hymenelia-species. This species may easily be mistaken for a non-lichenised ascomycete with minute black, angular apothecia, as the thallus is regularly present as an endoxylic discontinuous crust only. Vertical faces of coniferous stumps in upper montane forests are the preferred ecological niche, the ecology being similar to that of Calicium trabinellum, which is present as accompanying species on the cited specimen from Friuli.
Our specimen was collected at the bottom of the Piave Valley along the river, in a particular microclimatic condition (very humid and cold in winter, and dry-warm in summer). The species is currently included in the Italian red list of epiphytic lichens as "Endangered" (Nascimbene et al. 2013 This species, characterized by mostly whitish-grey minute almost granular areoles and lead-grey to blackish convex immarginate apothecia, is found on cushions of bryophytes on siliceous boulders and outcrops, mostly on N-facing slopes, from treeline to the alpine belt. Diagnostic for this species are the mostly brownish thallus with greenish-brownish, punctiform, flat, farinose soralia in combination with the lead-grey to blackish, convex, immarginate apothecia (recalling those of the type species of the genus, F. caesioatra, but larger and less convex). It grows on long-time moist sites from the montane belt to treeline, mostly on bark, more rarely on wood.  An arctic-alpine to boreal-montane, circumpolar lichen found on calciferous soil, mosses and plant debris, with optimum near and above treeline. It is usually sterile, with dark-grey to brownish thalli mainly consisting of small, suberect squamules which likely also act as vegetative diaspores. In old herbarium specimens, the triterpenoids often crystallize into long, translucent needles resembling glassy hairs, a diagnostic character to distinguish this species from sterile thalli of Massalongia carnosa.
A species of the G. leucaspis-group characterised by the entire (rather than radially incised) apothecial margins, and the elongate-fusiform (rather than acicular) ascospores. It is widespread in the Holarctic region, and in the Central European orobiomes it mostly occurs near or above treeline. In the Alps it seems to be most frequent in the eastern sector (Nimis et al. 2018a). Our specimen was collected on a steeply inclined, N-exposed rock in very moist, shaded, conditions, under overhangs. A circumpolar, arctic-alpine lichen occasionally found in the lower alpine belt of calcareous mountains, where it mostly settles on long-time humid, subvertical soil stripes. The ecology is similar to that of Ramonia melathelia which may grow next on plant remnants.
An often overlooked, but certainly uncommon species, perhaps more widespread in the Alps over calcareous substrata, with optimum near treeline. A probably holarctic species found on dolomite and hard limestone in rather sheltered situations, with optimum near treeline, as in the case of our record.
This species, widely distributed on both Hemispheres, is very similar to H. revoluta (for the main differences see Masson 2005), and some Italian records of the latter could refer to it. It seems to be widespread along the northern side of the Alps (Clerc 2006;Nimis et al. 2018a This sorediate and only rarely fertile species has a peculiar chemistry (atranorin and alectorialic acid, Poelt and Leuckert 1984), the latter causing a reddish miscoloration of the freshly yellowish-ochre areoles after some time of storage in the herbarium. It is a characteristic colonizer of overhangs of siliceous rocks, from treeline high up in the alpine belt, where Aspicilia mashiginensis, Lecanora orbicularis, L. swartzii, Psorinia conglomerata, and Sporastatia polyspora are among the accompanying species. It is fairly common in the siliceous mountains near the eastern border areas of the Alps, but apparently much rarer in the central and western parts. A mainly Mediterranean species found on smooth bark of broad-leaved trees. It is rarer in the Alps than in the Mediterranean mountains, as indicated by the few records from northern Italy. Our specimen was collected on isolated Fagus sylvatica trees.
A rarely collected species known from the Alps, the Central European mountains and Scandinavia, found beneath underhanging surfaces of siliceous rocks in upland areas; perhaps overlooked and more widespread in the Alps, being almost always sterile. Our specimen was collected on flint nodules in overhanging rocks of the late Jurassic formation "Formazione di Fonzaso". This species recalls L. alpigena, a large-fruiting species of the L. polytropa-group, but apothecial discs and margins are more discolourous, the discs being mostly reddish-brown, and the margins react P+ orange due to protocetraric acid;.the apothecia are often arranged in scattered groups on a poorly developed thallus. It grows on siliceous boulders including metal-rich rocks, mostly in the upper montane to lower alpine belts.
On steeply inclined surfaces of calcareous or basic siliceous rocks in seepage tracks, mostly in humid areas, as in our site.
This species seems to be restricted to high-elevation sites of the Alps and the Apennines, reaching the nival belt. An inconspicuous, perhaps overlooked, ephemeral lichen, previously known in Italy only from Trentino-Alto Adige/Südtirol (Nimis 2016;Nimis et al. 2018a).
A widespread species with an apparently disjunct distribution in mountain areas of the Northern Hemisphere, found on compact siliceous rocks wetted by rain in upland areas. It is locally abundant in the Alps, rarer in the Apennines. A circumpolar, arctic-alpine to boreal-montane lichen that at first sight is similar to Fuscopannaria praetermissa, but the thalli are mostly paler brown, often forming small rosettes, and the isidia-like lobules are less dense and mostly marginal. As the thalli are devoid of lichen substances, no extruding needle-like crystals develop with age, a diagnostic character to distinguish sterile herbarium specimens of both species under the dissecting microscope. Fertile thalli with red-brown, sessile apothecia are not rare, as in the specimen from Tuscany.
A temperate to probably circumboreal-montane species found on bark of conifers and Quercus spp. in humid forests, more rarely on wood. Included in the Italian red list of epiphytic lichens as "Data Deficient" (Nascimbene et al. 2013).

Miriquidica instrata (Nyl.) Hertel & Rambold
Lombardia • Brescia Prov., Adamello Natural Park, Passo del Tonale towards Passo del Paradiso; 46°15'10"N, 10°34'45"E;1950 m;24 Jul. 2006 This species is morphologically characterised by brown, slightly concave to flat, often compound areoles with paler greyish margins, recalling those of M. intrudens, but has aspicilioid apothecia, while the latter is sorediate. In early stages of development, it grows parasitically on a wide range of silicicolous crusts, including species of Aspicilia, Lecanora, Lecidea and Rhizocarpon. Later on, the lichenicolous behaviour may not be obvious. Preferred microhabitats are horizontal to slightly inclined rock faces of siliceous boulders, from the montane to the lower alpine belt. On mossy trunks of deciduous trees, more rarely on siliceous rocks, with a few records from the Italian Alps, probably locally overlooked. The three sites are located in the Prealps of Lombardy suggesting that the whole prealpine area of this region could potentially host this species. It was found in moist broadleaved forest stands.

Opegrapha vermicellifera (Kunze) J.R. Laundon
Veneto A mild-temperate lichen found on old trees in humid areas, especially near rivers, on faces seldom wetted by rain. In the Italian Alps it seems to be rare. In both regions our specimens were collected along a north exposed, deep valley, very close to a river. This chemically variable species grows on lime-free but mineral-rich siliceous rocks, mostly on sheltered, steeply inclined surfaces. The specimens from Passo delle Vette Grandi belong to the chemotype with stictic acid in addition to the common thiophaninic acid, and were collected on flint nodules or decalcified strata in overhanging rocks of the late Jurassic formation "Formazione di Fonzaso". A rather conspicuous species characterised by perithecioid apothecia sunken into yellowish-white, subglobose thalline warts reacting K+ yellow turning red, due to norstictic acid (Hanko 1983). It is regularly found encrusting bryophytes and plant debris over calciferous soil, mostly in the lower alpine belt.
A temperate species found on isolated deciduous trees with nutrient-rich bark, in montane valleys as in the case of our specimen.
An arctic-alpine, circumpolar lichen growing on soil and on moribund bryophytes on siliceous, base-rich or slightly calciferous soil (e.g. on calcareous schist), with optimum near and above treeline. It is certainly widespread through the Italian Alps, and also occurs in the central Apennines.
A poorly known species of the P. nigrum complex growing in humid-sheltered situations near or above treeline on basic siliceous or slightly calciferous rocks, as in our collection site. A Mediterranean (-montane) to mild-temperate lichen growing on steeply inclined seepage tracks of calcareous rocks, with a rather wide altitudinal range. Our specimens were collected on the Jurassic "Calcari Grigi" and "Rosso Ammonitico Superiore" formations.
A rarely recorded species. The taxonomic value of the genus Polysporina is so far unresolved (Westberg et al. 2015) and the generic placement of the species treated here appears to be provisional.
A mild-temperate to humid subtropical species found on calcareous rocks in damp and shaded habitats. Our specimen was collected on an N-exposed selciferous carbonatic rock in very moist, shaded conditions, together with other species with a trentepohlioid photobiont (e.g. Dirina massiliensis, very abundant, Gyalecta erythrozona, and G. hypoleuca).
A rarely collected species of calciferous rocks in upland areas. Its distribution in Italy, as well as in the Alps, is currently poorly known (Nimis et al. 2018a). This is the terricolous counterpart of the closely related saxicolous P. siebenhaariana, indicated by a sister position of both taxa in a phylogenetic reconstruction (Ekman and Blaalid 2011). It occasionally transgrades from mineral-rich soil layers covering strongly weathered calciferous rocks to solid rock, and then distinguishing both taxa may be difficult.
This lichen usually grows on weakly calciferous or base-rich siliceous rocks in upland areas, with optimum near and above treeline, but it may also occur on wood, as in the case of our collection. In the Italian Alps it is fairly common.
A circumboreal-montane species growing on hard rotting wood, e.g. on poles and fences, more rarely on Larix and Pinus cembra in the subalpine belt. This floristic note rectifies the erroneous attribution to Trentino-Alto Adige by Nascimbene et al. (2008).
An arctic-alpine, circumpolar lichen weak in competition, found on wet, naked soil, near glaciers or late snow-beds over acidic substrata.

Psorotichia lugubris (A. Massal.) Arnold
Friuli Venezia Giulia • Udine Prov., Julian Pre-Alps, high Torre-Valley above Tan Perhaps related to P. murorum, but with a verruculose to squamulose thallus and inconspicuous apothecia which are at first immersed, later prominent, and somewhat wider ascospores; overall distribution poorly known, with a few scattered records from the Alps.
This recently-resurrected species was often not distinguished from P. subrudecta in earlier studies. The predominantly marginal soralia and pruinose lobe tips are diagnostic. It grows on bark of isolated deciduous trees and is certainly widespread throughout Italy, including Mediterranean regions. This specis grows on exposed, subvertical faces of limestone and dolomite, including old monuments, in dry sites of the montane and subalpine belts. The total distribution extends to the Irano-Turanian Region.
A Mediterranean-Macaronesian species mainly found on twigs of shrubs and young trees in warm-humid Mediterranean areas. Our specimen was collected in a humid Quercus cerris forest. This species is regularly found on plant remnants in Caricion firmae-communities, mostly in humid, N-exposed sites. The ecology is similar to that of Gyalecta foveolaris, which has also been observed in the collection site.
A cool-temperate to arctic-alpine species growing on steeply inclined surfaces of base-rich, or weakly calciferous siliceous rocks. In Italy it is common in the subalpine and alpine belts, especially in the Alps. In our collection site it was abundant.
An invader of the thalli of Lecidea lapicida s lat. It may be distinguished from the macroscopically similar R. geographicum by the frequently angular apothecia with at least partly rough, umbonate to subgyrose discs, and the soon pigmented, mostly 3-septate ascospores. It is widespread in the siliceous Alps, mainly in the lower alpine belt, but apparently it was often overlooked.
A pioneer species of schistose, slightly calciferous or basic eruptive rocks in upland areas, which occasionally starts the life-cycle on members of Acarosporaceae, e.g. Acarospora sinopica when on metal-rich schists. On hard siliceous rocks near the ground in cold-humid habitats, sometimes on walls, mostly below the montane belt.
A cool-temperate to boreal-montane pioneer species, mostly found on smooth bark, but also on wood, with optimum in the subalpine and montane belts. An arctic-alpine to boreal-montane, perhaps circumpolar lichen found under overhanging cliffs of weakly calcareous or basic siliceous rocks, marl and calciferous schist near or above treeline.
An arctic-alpine to boreal-montane, perhaps circumpolar lichen found on limestone, marl and calcareous schists at and above treeline; widespread but not common in the Alps, where it can reach the nival belt, and also reported from the mountains of southern Italy. A mainly temperate species found on steeply inclined to underhanging, sunny surfaces of limestone and dolomite wetted by rain, sometimes also on pebbles on the ground, with optimum below the subalpine belt.

Rinodina luridescens (Anzi) Arnold
Liguria • Genova Prov., "in montibus di Reppia"; Caldesi leg.; MOD. A Mediterranean-Atlantic lichen described from Tuscany, found on hard siliceous rocks subject to frequent humid winds, often near the coast; not uncommon in some parts of Mediterranean Italy.
A Mediterranean-Atlantic lichen found on weakly inclined to horizontal surfaces of siliceous rocks wetted by rain, starting the life-cycle especially on Aspiciliella intermutans, but sometimes on other lichens, e.g. Rhizocarpon-species.
A submediterranean-Mediterranean epiphytic lichen which was overlooked or confused with similar species in the past. Our specimen was collected in an urban environment of the Po-Plain.
An arctic-alpine, circumpolar species found on soil, bryophytes and plant debris in tundra-like environments over siliceous substrata; certainly widespread throughout the Alps, and also reported from the high Mediterranean mountains. A temperate species found on asbestos-cement and mortar, often on walls, more rarely on dust-impregnated bark; easy to overlook, being often sterile.
An arctic-alpine, circumpolar species found on soil, bryophytes and plant debris over calcareous substrata in tundra-like habitats; widespread throughout the Alps. A widespread species growing on base-rich siliceous rocks, mostly on more or less calciferous sandstone, especially in nutrient-enriched situations such as on walls, tiles, brick or gravestones, mostly below the montane belt, also found in large conurbations.
This exsiccatum was erroneously cited by Mayrhofer and Poelt (1979) and Mayrhofer (1984) under Rinodina arnoldii. The species grows on siliceous rocks in upland areas, in moist and often shaded situations such as near waterfalls, rapids, gorges and shores of lakes, often associated with Cyanobacteria (Stigonema). An arctic-alpine, circumpolar lichen found on soil rich in humus and plant remains in tundra-like habitats.

Rinodinella dubyanoides (Hepp) H. Mayrhofer & Poelt
Puglia A humid subtropical to Mediterranean-Atlantic species growing on bark, often associated with bryophytes, on mossy rocks and soil in very humid situations, certainly worthy of protection in Italy, being included in the Italian red list of epiphytic lichens as "Vulnerable" (Nascimbene et al. 2013). In Northern Italy, it seems to be restricted to the eastern Alps where it is extremely rare.
On steeply inclined surfaces of calciferous rocks in upland areas, with several scattered records throughout the Alps (outside the Italian territory); known from the Central Apennines, probably more widespread in the Italian Alps.
A mainly temperate, ecologically broad-ranging pioneer species found on both calcareous and siliceous rocks and on thin layers of soil, occasionally also in periodically submerged sites. Our specimen was collected on mineral, poorly developed sandy soil abundantly colonised by Carex bicolor, indicative of periodically inundated conditions. Alpine thalli are usually thick, whitish pustulate, virtually sterile crusts reacting C+ red. The pustules soon become rough (sorediate state) and later rather frequently contain inconspicuous (often slightly pink), immersed ascomata, indicating that in some genera (e.g., Varicellaria, Lepra) soralia may be derived from ascomata. In the Alps, the species is mostly a coloniser of plant remains in alpine mats over acidic soils, with a preference for wind-exposed ridges. Over superficially decalcified substrata it may also occur on limestone or calcareous schists, as in the case of our site. On exposed calciferous rocks near or above treeline, e.g. on the top of large, isolated boulders and on steeply inclined to vertical surfaces.
A probably circumboreal freshwater species, submerged only for very short periods, mostly found along creeks, on mineral-rich siliceous rocks, more rarely on calcareous substrata.
This species forms sterile thalli with whitish convex areoles reacting K+ yellow, P+ orange-red and UV-(due to the presence of atranorin and fumarprotoetraric acid), and becoming apically sorediate with coarse soredia, the outermost ones often being slightly bluish. Frequently the thalli are parasitized by Tremella lichenicola and the presence of its galls is a good hint as to the identity of the host. V. fucata colonises both the bark of a wide range of trees and wood (e.g. rotting snags), in Central Europe from the colline to the montane belt.
A mainly boreal-montane species found on decaying, decorticated but still hard wood, mostly of conifers, especially near the base, or on fallen trunks, with optimum near treeline.

Discussion
The list includes 225 records of 153 taxa. Twenty taxa are new to Italy, the others are new to one or more administrative regions; the latter include 15 second records and 5 third records for Italy.
Most records are from the alpine belt (61 records, 55 taxa), followed by the subalpine (53, 44 taxa) and montane (53, 36 taxa) belts. This is due to the fact that the research activity of most of the authors is mainly centred on the Alps (e.g. Nascimbene et al. 2017;Nimis et al. 2018a;Saiz et al. 2021).
4. Species of biogeographic interest, which in Italy (or in some regions) are near the limits of their climatic optima. Most of the nationally or regionally rare lichens belong to an oceanic-suboceanic element with tropical affinities, or to a small set of continental species with their optima in the dry steppe biome, which suggests that many rare species can persist in microrefugia, i.e. sites with microclimates that support small populations of species beyond the boundaries of the climatic limits of their main distributions. This is the case of Bacidina delicata, Fuscopannaria praetermissa, Lecanora horiza and Sticta limbata, which are at the limit of their bioclimatic ranges (suboceanic and/or Mediterranean) in a continental-alpine region such as Trentino-Alto Adige, of Fuscopannaria ignobilis, mainly Tyrrhenian, a suboceanic species which is obviously restricted to a few humid sites in Molise, of Rinodina oleae, a mainly Mediterranean species, which is at the limit of its bioclimatic range in Emilia, and of Usnea flavocardia, a subatlantic species restricted to a few sites in Tyrrhenian Italy. Another example is that of C. arbuscula and C. mitis, two arctic-alpine to boreal-montane species which are widespread and common in the Alps, but are near their southern distributional limit in the Marche region (Northern Apennines). Similar is the case of R. olivaceobrunnea, an arctic-alpine species which finds the southernmost limit of its Italian distribution in the mountains of Calabria. As already observed by Aptroot and van Herk (2007) in the Netherlands, these species are those for which climate change is most likely to modify their relative patterns of commonness/rarity. 5. Species bound to rare habitats, such as old-growth forests. This is the case of e.g. Arthonia vinosa, Calicium adspersum, Cetrelia chicitae, Chaenotheca brachypoda, C. brunneola, C. phaeocephala, Chaenothecopsis debilis, Mycobilimbia epixanthoides, Scutula circumspecta, Sphinctrina leucopoda, plus some of the species listed under the previous point. Also in this case, these species are generally rare, their rarity being mainly due to the strong contraction of their habitat.
Our results indicate that, even in historically well-explored areas it is still possible to discover several new species. Even small, previously well-studied sites may provide interesting surprises. This is the case of the small plot in the Vette Feltrine (Pre-Alps, Dolomiti Bellunesi National Park), which consists of a few square meters of rock outcrops, within a peculiar site with abundant precipitations due to humid air masses from the Adriatic Sea that originate frequent fog. The collections were carried out on a NE exposed slope where the rock outcrops contain both a calciferous (dominant) and a siliceous (flint nodules and strata) component, with an alternation of exposed and protected overhanging parts that correspond to diverse microhabitats for lichens, also providing refugia for microthermic species. Another emblematic case is represented by the Paneveggio-Pale di San Martino Natural Park, an area with a very humid climate and heterogeneous geological features, that was intensively explored by Ferdinand Arnold at the end of the 19 th century (Dalla Torre and Sarnthein 1902) and also in recent times in the framework of studies mainly focused on lichen ecology in forest ecosystems (e.g. Nascimbene et al. 2008;Nascimbene et al. 2009). On one hand, these examples indicate that repeated, intensive, surveys are needed to reach exhaustive knowledge even of small sites. On the other hand, they indicate that further exploration should prioritise areas with rare climatic conditions and heterogeneous rock composition, corroborating the view that high geo-diversity, even at a small spatial scale, corresponds to high lichen diversity (Spitale and Nascimbene 2013).

Conclusion
The picture of the lichen biota of Italy now has new pixels, but its grain is still coarse. On one hand, herbaria, especially when digitized, are an irreplaceable tool for further data mining allowing the re-evaluation of old records in the light of the progress of phylogenetic hypotheses and taxonomy, and should be therefore sustained and implemented with new records (see e.g. Crisci et al. 2020). On the other hand, professional floristics should gain more consideration in the scientific community, acknowledging its fundamental role in providing and updating occurrence and distributional data, which are the basis for new biogeographic hypotheses, taxonomic and ecological research, and biodiversity conservation.