Italy’s Hidden Biodiversity Surges as New Algae, Mosses, Fungi and Lichens Turn Up Across the Country

Italy’s smallest and least glamorous organisms are having a moment. A sweeping new instalment of the country’s long-running floristic inventory, published in the journal Italian Botanist, documents dozens of new records and rediscoveries spanning algae, bryophytes, fungi and lichens, from the depths of Lake Iseo to the shaded limestone faces of the Colli Berici. The contribution, the twenty-first in the series, assembles field observations from dozens of botanists and mycologists across the peninsula and its islands, and several of the records redraw distribution maps in ways that surprise even the specialists who compiled them.

The headline discovery concerns a stonewort. Chara globata, a perennial green alga that forms dense submerged meadows in permanent water bodies, has been recorded for the first time in Italy, and indeed for the first time anywhere in western Europe, at the Torbiere del Sebino Nature Reserve near Iseo in Lombardy. The species grows on fine muddy sediments in neutral to alkaline waters under oligo- to meso-eutrophic conditions, from freshwater to slightly brackish environments. In Lake Iseo it was found at depths of three to four metres, forming dense stands alongside Chara globularis and Najas major, a plant community referable to the alliance Charion intermediae. The European Red List of Charophytes assesses C. globata as Near Threatened, and until now it was known only from Croatia, North Macedonia, Romania, Ukraine and Russia. Its appearance in the Italian lake significantly extends the known range of a species already considered at risk across the continent.

The algal records do not stop there. Three species of the desmid genus Closterium, delicate single-celled algae with gracefully curved cells, were newly documented in Calabria. Closterium aciculare, a tolerant species that adapts well to eutrophic waters, turned up in the sediment of an irrigation tank at Motta San Giovanni, while C. dianae was collected from a Sphagnum carpet near a spring at Oppido Mamertina. More striking still is Closterium karnakense, found in an irrigation tank at Macellari with alkaline water and a conductivity of 780 microsiemens per centimetre, indicating a high concentration of dissolved salts. The species was originally described from a salty lake in Egypt and has never before been reported in Italy in the scientific literature. It closely resembles C. dianae but lacks the end-pore and carries a folded chloroplast that leaves the cell extremities empty.

From the Venice Lagoon comes another first for the Mediterranean Basin. Ulva capillata, a tubular green seaweed with filigree thalli that form dense mats on hard substrates such as stones and mussel shells, was collected in the intertidal zone of the Lido as early as 2019 and initially deposited in the herbarium simply as Ulva sp. A recent comparison of the DNA barcode region tufA showed a one hundred percent match between the Italian voucher and the holotype sequence of the species. Until now U. capillata was known in Europe only from Denmark, Norway, Sweden, the Netherlands and Belgium, making the Venetian record a remarkable north-to-south jump for a species apparently at home in colder Atlantic waters.

The bryophyte section of the contribution is the largest, and it mixes good news with warnings. Buxbaumia viridis, a small epixylic moss that grows on logs in an advanced state of decay, was found for the first time in Basilicata, in a protected old-growth forest with long ecological continuity on Monte Cozzo Ferriero. The species is protected under Annex I of the Bern Convention and Annex II of the Habitats Directive, and it is listed as Near Threatened in the recent Italian Red List. Dicranum muehlenbeckii, a rare snow-bed moss recorded in all Alpine regions except the Valle d’Aosta, was finally documented there at 2,250 metres on the Colle del Piccolo San Bernardo, where it is listed as Endangered nationally. Geheebia gigantea, another Red List species assessed as Endangered, appeared for the first time in Friuli Venezia Giulia in the Carnic Alps.

Not all bryophyte news is reassuring. Campylopus introflexus, the most widespread invasive moss in Europe, has now reached Friuli Venezia Giulia, found on damp sand at Lignano Riviera. The species originates from the southern hemisphere, where it still occurs in Australia, New Zealand, South Africa and South America. It was imported into England in 1941 and spread from there across most of Western Europe, invading anthropogenic habitats. The first Italian record dates back to 1956 in the Villa Maria Park in Ischia, probably introduced with exotic plants cultivated in the park, and the species has since spread to thirteen administrative regions. Its arrival in yet another region underlines how thoroughly biological invasions have penetrated even the moss layer of the Italian landscape.

Some records are rediscoveries rather than firsts. Crossidium crassinervium was confirmed for Sardinia more than 185 years after Giuseppe De Notaris first reported it in the hills around Cagliari in 1838. In Liguria, two calcicolous mosses of the genus Flexitrichum were confirmed within current regional borders for the first time in more than 160 years, the only previous Ligurian record of F. flexicaule coming from Colle di Tenda, a locality now lying on the border between France and Piedmont. Grimmia orbicularis was likewise confirmed in Liguria more than eighty years after the last record. Cladonia peziziformis, a reindeer lichen relative, was rediscovered in the Val Bisagno near Genoa, close to collection sites worked by the nineteenth- and twentieth-century lichenologist Camillo Sbarbaro, confirming the species after more than fifty years and correcting an erroneous modern record in the process.

The fungal records reveal how much remains unknown even in well-studied groups. Three species new to Calabria, Clavaria falcata, Inocybe griseolilacina and Lepiota grangei, were all found within the Botanical Garden of the University of Calabria in Rende, a reminder that unexpected biodiversity can surface in managed landscapes. More spectacular are the lichenicolous fungi, specialized parasites that live on lichens. Tremella lichenicola, which induces conspicuous dark galls on the crustose lichen Violella fucata, was recorded in Italy for the first time, from the Carnic Alps and the Ligurian Alps. Tremella phaeophysciae, which forms brownish galls on Phaeophyscia orbicularis, was also reported for the first time in the country. Phacopsis lethariellae, a very rare parasite restricted to the host lichen Lethariella intricata and previously known in Italy from a single Calabrian locality, was found at two sites in Basilicata, its blackberry-like black galls up to twice as wide as the host’s branches making it easy to spot in the field.

Several of the parasitic Tremella records came not from fresh fieldwork but from the re-examination of historical herbarium specimens collected by Josef Hafellner between 1954 and 2001, with labels written in German. Tremella cetrariicola, confined to the lichen Tuckermannopsis chlorophylla, was newly documented for four regions from specimens gathered decades ago, and Tremella hypogymniae, restricted to Hypogymnia physodes, was added to three more. The pattern illustrates a quiet revolution in Italian biodiversity science: museum drawers and herbarium folders, revisited with modern taxonomic knowledge, can yield new regional and national records without a single new field trip. Because the hosts are widely distributed in the Italian Alps, researchers expect the parasites to turn up in further regions, even though they are certainly not common.

The lichen section rounds out the picture with a cluster of discoveries from the Colli Berici near Vicenza, where a single July 2025 excursion by Michele Tretiach and Simone Ceseri yielded six species new to Veneto, including the euendolithic Bagliettoa steineri, which lives inside hard compact limestone, and Gyalecta thelotremella, an inconspicuous species whose new collections extend its range to northern Italy for the first time. Elsewhere, Polyblastia sendtneri, a circumpolar arctic-alpine species of exposed subalpine habitats, was recorded for the first time in southern Italy on the limestone pastures of Mount Timpone di Viggianello in Calabria, and the recently described Swinscowia endolithea, previously known only from southern France and the Trieste coast, appeared on shaded limestone in Veneto. Taken together, the twenty-first instalment of the series shows that Italy’s cryptic flora, from stoneworts to lichen parasites, is still being mapped in real time, and that careful fieldwork, DNA barcoding and the patient re-reading of old herbarium labels remain among the most productive tools for discovering it.

Subject of Research: New distribution records of algae, bryophytes, fungi and lichens in the Italian flora

Article Title: Notulae to the Italian flora of algae, bryophytes, fungi and lichens: 21

Article References: Notulae to the Italian flora of algae, bryophytes, fungi and lichens: 21. (n.d.). https://doi.org/10.3897/italianbotanist.21.196260

Image Credits: AI Generated

DOI: 10.3897/italianbotanist.21.196260

Keywords: Italian flora, algae, bryophytes, fungi, lichens, biodiversity, floristic records, Chara globata, Ulva capillata, lichenicolous fungi, invasive moss, Italy