The future of plant diversity within a Mediterranean endemism centre: Modelling the synergistic effects of climate and land-use change in Peloponnese, Greece.

Climate- and land-use change stand as primary threats to terrestrial biodiversity. Yet, their synergistic impacts on species distributions remain poorly understood. To address this knowledge gap, we conducted the first-ever comprehensive species distribution analysis on an entire regional endemism centre within an eastern Mediterranean country, incorporating dynamic land-use/land-cover change data together with climate change scenarios. Specifically, we apply species distribution modelling and spatial data analysis techniques to compare the individual and synergistic effects of these environmental drivers on the endemic vascular flora of Peloponnese, focusing on potential range contractions, altitudinal shifts, and habitat fragmentation levels. Moreover, we identify fine-scale present and potential future endemism hotspots within our study area, incorporating taxonomic and phylogenetic information. Overall, we aim to enhance our current understanding of endemism patterns and contribute to the development of future-proof conservation strategies for safeguarding Greece's endangered endemic flora. The integration of land-use change projections with climate change yielded less severe impacts compared to the effects anticipated when considering climatic variables alone. Most taxa are expected to undergo significant range declines and nearly half might experience increased habitat fragmentation, due to the synergistic effects of climate- and land-use change. We identified endemism hotspots, which are concentrated in or along the main Peloponnesian mountain massifs. However, our predictions indicate that areas presently recognized as endemism hotspots will undergo a concerning area decline, across all future scenarios considered in this study. Our findings highlight the importance of including dynamic land-use variables alongside climatic predictors when projecting species distributions under global change. Moreover, we showed that endemism hotspots are not static and considering their potential geographic shifts is paramount to delineate effective forward-looking conservation strategies.

A new combination for a neglected member of Linaria subsect. Versicolores (Plantaginaceae, Antirrhineae) endemic to the Algarve, Portugal.

Linariabimaculata comb. et stat. nov., from the overlooked Central Algarve plant endemism centre, is here lectotypified and redescribed as a full species based on Linariaviscosavar.bimaculata, which was historically misidentified under allopatric L.spartea and L.viscosa. Traditional herbarium taxonomy and citizen science observations were combined to document the geographical range of the four species of Linariasubsect.Versicolores in the Algarve and amend an identification key for the Iberian clade of this subsection. Geographical patterns and morphological similarity suggest a sister relationship between L.bimaculata and L.algarviana, unveiling a new possible example of parallel speciation linked to a purple to yellow shift in corolla colour. Besides the yellow flowers, L.bimaculata differs from L.algarviana in the more elongate fertile stems and the invariably erect-patent corolla tube. It is assessed as Vulnerable (VU) according to the IUCN Categories and Criteria.

Tourist Trampling on a Peripheral Plant Population Restricted to an Urban Natural Area in the Capo Sant'Elia Promontory (Sardinia, W-Mediterranean Basin).

Urban natural areas provide important ecological services such as biodiversity conservation, as well as opportunities for people to connect with nature and preserve cultural heritage. However, the increasing demand for access to natural areas and the expansion of human recreational activities, such as hiking and biking, pose threats to these ecosystems, especially for animal and plant species, finally resulting in biodiversity loss. This study explores the intricate link between human trampling, plant density, and the morphological and reproductive characteristics of Globularia alypum L., a plant with a peripheral population in Sardinia restricted to a natural area within an urban context. The study examined trampling effects on 75 plots along a frequently used path crossing the plant's core population. Similar environmental conditions were assumed, with differences attributed to human trampling intensity and plant density, and morphological and reproductive traits were measured within each plot. Our results showed that human trampling caused differences in the morphological traits of plants, whereas, in contrast, reproductive traits are less vulnerable to human trampling than morphological ones. As a result, trampled areas may experience decreased plant recruitment, which can have long-term implications for plant population dynamics. Understanding the relationship between trampling effects and the sensitivity of peripheral plant populations is crucial for effective conservation and management strategies.

Seed germination and vegetative and in vitro propagation of Hieracium lucidum subsp. lucidum (Asteraceae), a critically endangered endemic taxon of the Sicilian flora.

Hieracium lucidum subsp. lucidum is a critically endangered endemic taxa of the Sicilian flora. It is a relict of the Tertiary period surviving on the cliffs of Monte Gallo (NW-Sicily). This research focused on finding the best protocols for seed germination and vegetative and in vitro propagation to contribute to ex situ conservation. Seed germination tests were carried out using constant temperatures of 15 °C, 20 °C and 25 °C in continuous darkness and an alternating temperature of 30/15 °C (16 h/8 h, light/dark). The seeds had no dormancy, and a high germination capacity (70-95%) was obtained at all tested thermoperiods. The possibility of vegetative propagation of the taxon was evaluated through the rooting capacity of stem cuttings treated or not treated with indole-3-butyric acid (IBA). All cuttings were treated with IBA rooted within 2 months, while only 50% of the untreated cuttings were rooted within a longer time. An efficient protocol for rapid in vitro propagation from leaf portions was developed. The response of explants was tested on hormone-free Murashige and Skoog (MS) basal medium and MS enriched with different types of cytokinins: 6-Benzylaminopurine (BAP) and meta-Topolin (mT) in combination with naphthaleneacetic acid (NAA) and 2,4-Dichlorophenoxyacetic acid (2,4-D) at the same concentration. The combination of mT (2 mg L-1) and 2,4-D (1 mg L-1) in the medium was the most effective and showed the highest percentage of callus induction and the mean number of regenerated shoots. The maximum rate of root regeneration and the maximum number and length of roots were obtained on hormone-free MS and MS enriched with IBA at concentrations of 1 mg L-1. From the results obtained, it can be concluded that H. lucidum subsp. lucidum can be successfully propagated using one of the tested techniques, subject to the availability of the material for reproduction.

Species Delimitation in a Polyploid Group of Iberian Jasione (Campanulaceae) Unveils Coherence between Cryptic Speciation and Biogeographical Regionalization.

Groups with morphological stasis are an interesting framework to address putative cryptic species that may be hidden behind traditional taxonomic treatments, particularly when distribution ranges suggest disjunct and environmentally heterogeneous biogeographic patterns. New hypotheses of delimitation of evolutionary independent units can lead to the identification of different biogeographic processes, laying the foundation to investigate their historical and ecological significance. Jasione is a plant genus with a distribution centered in the Mediterranean basin, characterized by significant morphological stasis. Within the western Mediterranean J. gr. crispa species complex, J. sessiliflora s.l. and allied taxa form a distinct group, occupying environmentally diverse regions. At least two ploidy levels, diploid and tetraploid, are known to occur in the group. The internal variability is assessed with phylogenetic tools, viz. GMYC and ASAP, for species delimitation. The results are compared with other lines of evidence, including morphology and cytology. The fitting of distribution patterns of the inferred entities to chorological subprovinces is also used as a biogeographical and environmental framework to test the species hypothesis. Despite the scarcity of diagnostic morphological characters in the group, phylogenetic delimitation supports the description of at least one cryptic species, a narrow endemic in the NE Iberian Peninsula. Moreover, the results support the segregation of a thermophilic group of populations in eastern Iberia from J. sessiliflora. Ploidy variation from a wide geographical survey supports the systematic rearrangement suggested by species delimitation. Taxonomic reorganization in J. sessiliflora s.l. would allow ecological interpretations of distribution patterns in great accordance with biogeographical regionalization at the subprovince level, supporting geobotanical boundaries as a framework to interpret species ecological coherence of cryptic lineages. These results suggest that species differentiation, together with geographic isolation and polyploidization, is associated with adaptation to different environments, shifting from more to less thermophilic conditions. Thus, the recognition of concealed evolutionary entities is essential to correctly interpret biogeographical patterns in regions with a complex geologic and evolutionary history, such as the Mediterranean basin, and biogeographical units emerge as biologically sound frameworks to test the species hypothesis.

Taxonomic and ecological remarks on Solenopsisbivonae species complex (Campanulaceae).

The populations usually attributed to Solenopsisbivonae (Tineo) M.B.Crespo, Serra & A.Juan are investigated from a taxonomical and morphological viewpoint. Within this species complex, four new subspecies occurring in Sicily and Calabria are recognized, such as subsp. bivonae, subsp. madoniarum, subsp. peloritana and subsp. brutia. In addition, a new species from Cyprus described as S.meikleana and S.bacchettae from Sardinia must be included in this group. The synonymy, typification, description, seed testa morphology, chorology, ecology, illustrations, conservation status, and examined specimens for each taxon are provided. Besides, the analytical keys, distribution maps, and phytosociological arrangement regarding these taxa are given too.

New Data on Native and Alien Vascular Flora of Sicily (Italy): New Findings and Updates.

In this paper, based on fieldwork and herbaria surveys, new data concerning the presence of 32 native and alien vascular species for Sicily (Italy) are provided. Among the native species, the occurrence of the following taxa is reported for the first time or confirmed after many decades of non-observation: Aira multiculmis, Arum maculatum, Carex flacca subsp. flacca, Mentha longifolia, Oxybasis chenopodioides, Najas minor and Xiphion junceum. Furthermore, we document the presence of three native species (Cornus mas, Juncus foliosus and Limonium avei) that, despite being repeatedly observed in Sicily and reported in the literature, are inexplicably omitted by the most recent authoritative checklists regarding the flora of Italy. Finally, fifteen alien species new to Sicily (including one new to Europe, i.e., Pyrus betulifolia) are reported and seven poorly documented allochthonous taxa are confirmed for the island, and for two of them, a status change is proposed. These new or confirmed records allow us to better define the European and national distribution of the targeted taxa and offer new insights on the native and alien flora of Sicily.

Nomenclature and Typification of the Jasione L. (Campanulaceae) Groups from the Eastern Mediterranean Basin.

In this research, all the published names of Jasione (Campanulaceae) in the species, subspecies, and variety ranks for populations from the Balkan and Anatolian peninsulas are reviewed, including names of taxa allied to these groups in surrounding areas. These two areas are among the main centers of diversity of the genus, albeit no recent revisions to address the regional taxonomical complexity of the genus have been published for the Balkans and Anatolia. In this work, the taxonomic status and typification of twenty-six published names are discussed, including the plethora of names within the Jasione heldreichii, J. supina, and J. orbiculata taxonomic complexes. In total, eleven lectotypes and one neotype are designated for names from the aforementioned regions, plus one from southern Italy. This nomenclatural clarification establishes a reference for ongoing and future taxonomic and evolutionary studies of Jasione in the Mediterranean basin. In a genus prone to micro-endemism and cryptospeciation, a number of the historically described forms, despite being disregarded by current taxonomic treatments, may, therefore, deserve further attention.

Nomenclatural Synopsis, Revised Distribution and Conservation Status of Ranunculus gracilis (Ranunculaceae) in Italy.

Ranuculus gracilis is endemic to the SE Euro-Mediterranean area and its presence in Italy is controversial. Based on analysis of the relevant literature, field surveys and examination of herbarium specimens, a revised distribution of this species in Italy is presented and its conservation status is assessed. Ranunculus agerii, described by Antonio Bertoloni from Bologna (Emilia-Romagna, Northern Italy), and R. schowii, described by Vincenzo Tineo from Vittoria and Terranova (Sicily), usually regarded as synonyms of R. gracilis, are here lectotypified and their taxonomic status discussed. Thanks to our study, the presence of R. gracilis in Italy is confirmed and, now, it is reported in a national conservation framework.

Variability and Nativeness in the Mediterranean Taxa: Divergence and Phylogeography of Genista etnensis (Fabaceae) Inferred from Nuclear and Plastid Data.

Genista etnensis is a remarkable and well-known tree endemic to Sicily, Sardinia, and Corsica (Mediterranean Basin). Nevertheless, its morphological variability and its native status throughout its range need to be further investigated. In this study, we aim to clarify some aspects of this infraspecific variability by molecular means. Sequences of one nuclear and five plastid markers were analyzed under maximum parsimony by using TCS software. Plastid data were also time-calibrated under a Bayesian Inference framework. Plastid data revealed strong isolation between the populations from the Cyrno-Sardinian biogeographical province, which are also the most diverse and presumably the most archaic, and those from Sicily and Southern Italy (in this latter area, the species is naturalized). The calibration analysis indicates that the last common ancestor between G. etnensis and its sister group G. fasselata dates back to the middle Pliocene or slightly later, when sclerophyllous Mediterranean vegetation spread, whereas G. etnensis itself might have originated in the middle Pleistocene. The current, rather unusual distribution of G. etnensis could be explained by long-range seed dispersal from the western part of the range or by anthropogenic introduction into Sicily, with extinctions of transported haplotypes in the region of origin. Interestingly, the Vesuvius population, introduced from Sicily in recent times and locally naturalized, shows private genotypes, and was richer in both genotypes and haplotypes than the Sicilian ones.

The IUCN Green Status of Species: A Call for Mediterranean Botanists to Contribute to This New Ambitious Effort.

In the Mediterranean Basin, a critical focal point for the conservation of plant diversity, there has been a large increase in practical conservation actions for many plant species to prevent extinction and to improve their conservation status; quantifying the effectiveness of these initiatives in reversing species declines is urgently important. In 2021, the International Union for Conservation of Nature (IUCN) launched a new tool that allows the impact of conservation actions on plant species to be assessed. The Green Status of Species is a new set of metrics under the Red List of Threatened Species that assigns species to recovery categories, complementary to the classic extinction risk categories. Crucially, the Green Status of Species provides methods to evaluate the impact of past conservation, and the potential for future conservation impact, on species status and recovery in a standardized way. Considering the efforts made so far for the conservation of Mediterranean threatened plants, using the Green Status of Species would be highly useful to direct future conservation policies. We, therefore, encourage botanists and practitioners working on threatened plants in the Mediterranean area to use this new assessment tool to inform conservation and recovery programs.

Biodiversity in Urban Areas: The Extraordinary Case of Appia Antica Regional Park (Rome, Italy).

The first inventory of the flora of Appia Antica Regional Park (Italy), one of the largest protected urban areas in Europe (4580 ha), its biological, ecological and biogeographical composition, and notes of the vegetation physiognomies and landscape are presented; physical characteristics of the territory (geomorphology, lithotypes, and phytoclimate) are also given. The landscape is defined by an agricultural matrix with natural and seminatural areas as patches, and riparian vegetation communities as corridors. The vegetation physiognomies are represented by types linked to the Mediterranean climate (mixed, Mediterranean, and riparian forests; scrubby, rocky, aquatic, and helophytic vegetation; anthropogenic communities). The floristic list includes 714 taxa (104 families and 403 genera). Therophytes prevail over hemicryptophytes; woody flora comprises about 30% of alien species. As regards chorotypes, together with a considerable number of Mediterranean species, there are many exotic species with wide distribution areas testifying to a long-lasting anthropic impact. Floristic novelties (european, national, and regional levels) for 21 taxa are reported. The extraordinary species diversity discovered (43% of flora of Rome and 20% of regional flora) is linked to the landscape heterogeneity, the characteristics of which are: (1) persistence of residual natural patches, (2) occurrence of quite well-preserved aquatic habitats and humid meadows, (3) a rich anthropogenic flora, (4) an interesting flora of archeological sites, (5) occurrence of species not common in Latium, (6) occurrence of populations of aliens in crops (which cause economic impact), (7) presence of aliens on archeological ruins (which cause economic-social impacts). The extensive set of data provided represents a general base framework for guiding future research efforts and landscape action plans consistent with environmental sustainability.

Seed Morphology in Species from the Silene mollissima Aggregate (Caryophyllaceae) by Comparison with Geometric Models.

The description of seed shape by comparison with geometric models allows shape quantification, providing the means for an accurate comparison between different species or populations. Geometric models described for the lateral and dorsal views of the seeds of Silene species are applied to the quantification of the shape in the seeds belonging to twenty populations of the eleven taxa of S. mollissima aggregate. Cardioid models LM1, LM5 and LM6 adjust differentially to the lateral views of the seeds, while models DM1, DM5 and DM6 are applied to the dorsal views of the seeds. Quantification of the lateral view of seeds with LM5 results in two groups of species of different geographic origin. The seeds more resembling DM5 include S. andryalifolia, S. badaroi, S. gazulensis, S. hifacensis and S. tomentosa, i.e., the taxa with a continental distribution from southern Spain to northern Italy; in contrast, the group of seeds with lower similarity to DM5 includes those from species in northern Africa and the Mediterranean Tyrrhenian islands: S. auricolifolia, S. hicesiae, S. ichnusae, S. mollissima, S. oenotriae and S. velutina. The description of the seed shape based on geometric models contributes to investigating the relationships between related species and constitutes a promising technique for taxonomy.

The Endemic Vascular Flora of Sardinia: A Dynamic Checklist with an Overview of Biogeography and Conservation Status.

The vascular flora of Sardinia has been investigated for more than 250 years, with particular attention to the endemic component due to their phylogeographic and conservation interest. However, continuous changes in the floristic composition through natural processes, anthropogenic drivers or modified taxonomical attributions require constant updating. We checked all available literature, web sources, field, and unpublished data from the authors and acknowledged external experts to compile an updated checklist of vascular plants endemic to Sardinia. Life and chorological forms as well as the conservation status of the updated taxa list were reported. Sardinia hosts 341 taxa (15% of the total native flora) endemic to the Tyrrhenian Islands and other limited continental territories; 195 of these (8% of the total native flora) are exclusive to Sardinia. Asteraceae (50 taxa) and Plumbaginaceae (42 taxa) are the most representative families, while the most frequent life forms are hemicryptophytes (118 taxa) and chamaephytes (106 taxa). The global conservation status, available for 201 taxa, indicates that most endemics are under the 'Critically Endangered' (25 taxa), 'Endangered' (31 taxa), or 'Least Concern' (90 taxa) IUCN categories. This research provides an updated basis for future biosystematics, taxonomic, biogeographical, and ecological studies and in supporting more integrated and efficient policy tools.

Allium ducissae (A. subgen. Polyprason, Amaryllidaceae) a New Species from the Central Apennines (Italy).

In this paper, Allium ducissae (the LSID for the name Allium ducissae is: 77254606-1) is described as a new species based on morphological and molecular analyses, and its taxonomic relationships are discussed. It grows in crevices on calcareous rocks, rocky slopes and grassy ledges in the subalpine belt, within two regional protected areas in the Lazio and Abruzzo administrative regions (Central Apennines, Italy). Previously, these populations were attributed to A. strictum, a species described from Siberia, belonging to A. sect. Reticulatobulbosa. The new species is distinct from A. strictum in the morphology of vegetative and reproductive structures. Indeed, it is close to A. palentinum, an endemic species to Cantabrian Mountains (NW Spain). Both molecular and morphological data support the recognition of the Allium populations coming from the Central Apennines as a new species. Allium ducissae can be clearly distinguished from A. palentinum by longer and wider tepals, longer filaments, tooth of inner filament, flower pedicels, spathe appendage, and smaller seeds. Moreover, seed testa micro-sculptures revealed slight differences between A. ducissae and A. palentinum. Chromosome counts showed that A. ducissae is diploid with 2n = 16 chromosomes, as already known for A. palentinum. Molecular analyses support the affiliation of A. ducissae and A. palentinum to A. sect. Falcatifolia, contrary to what is known for the latter species, usually included in A. sect. Daghestanica. Finally, the IUCN assessment for the newly described species is proposed and briefly discussed.

Importance of Plants with Extremely Small Populations (PSESPs) in Endemic-Rich Areas, Elements Often Forgotten in Conservation Strategies.

The distribution of the threatened fern Ophioglossum vulgatum L., a plant with extremely small populations (PSESPs) in Sardinia, is characterized by small disjunct populations with only a few individuals, and little is known about its status in the wild. To provide information for the conservation of O. vulgatum and with the aim to develop an in situ conservation strategy, we investigated its distribution, population size, and habitat. Field surveys confirmed that the species grows in only five localities. Two representative populations were selected for this study (Funtanamela and Gedili), and in each population, all plants were mapped and monitored monthly from April to August over an 8-year period. During the study, the populations had a very low number of reproductive plants and the populations appeared to be in decline, with the total number of plants per population slightly decreased in Gedili while a sharp reduction was recorded in Funtanamela due to wild boar threat. A fence was built in order to protect the site from further damage, but no noticeable signals of recovery were observed. The most urgent conservation requirement for this species is to preserve the threatened habitat of the remnant populations. Further field surveys and research are also required for an improved understanding of the species' status.

Aquatic Macrophytes Occurrence in Mediterranean Farm Ponds: Preliminary Investigations in North-Western Sicily (Italy).

Mediterranean wetlands are severely affected by habitat degradation and related loss of biodiversity. In this scenario, the wide number of artificial farm ponds can play a significant role in the biodiversity conservation of aquatic flora. In the present contribution we show the preliminary results of a study on Mediterranean farm ponds of north-western Sicily (Italy), aimed to investigating the environmental factors linked to the occurrence of submerged macrophytes (vascular plants and charophytes). We studied the aquatic flora of 30 ponds and determined the chemical and isotopic composition of their water bodies on a subset of the most representative 10 sites. Results show that (1) farm ponds host few but interesting species, such as Potamogeton pusillus considered threatened at regional level; (2) Chara vulgaris, C. globularis and P. pusillus behave as disturbance-tolerant species, occurring both in nitrates-poor and nitrates-rich waters, whereas Stuckenia pectinata and Zannichellia palustris occur only in nitrates-poor waters. Although farm ponds are artificial and relatively poor habitats, these environments seem to be important for the aquatic flora and for the conservation of the local biodiversity, and can give useful information for the use of macrophytes as bioindicators in the Mediterranean area.

Plant Endemism Centres and Biodiversity Hotspots in Greece.

Biodiversity hotspots (BH) cover a small fraction of the Earth's surface, yet host numerous endemics. Human-induced biodiversity loss has been increasing worldwide, despite attempts to halt the extinction crisis. There is thus an urgent need to efficiently allocate the available conservation funds in an optimised conservation prioritization scheme. Identifying BH and endemism centres (EC) is therefore a valuable tool in conservation prioritization and planning. Even though Greece is one of the most plant species-rich European countries, few studies have dealt with the identification of BH or EC and none has ever incorporated phylogenetic information or extended to the national scale. Consequently, we are unaware of the extent that Special Areas of Conservation (SAC) of the Natura 2000 network efficiently protect Greek plant diversity. Here, we located for the first time at a national scale and in a phylogenetic framework, the areas serving as BH and EC, and assessed the effectiveness of the Greek SAC in safeguarding them. BH and EC are mainly located near mountainous areas, and in areas supposedly floristically impoverished, such as the central Aegean islands. A critical re-assessment of the Greek SAC might be needed to minimize the extinction risk of the Greek endemics, by focusing the conservation efforts also on the BH and EC that fall outside the established Greek SAC.

Nomenclatural Synopsis of Cirsium Sect. Eriolepis (Asteraceae) in Italy.

The names of the Italian taxa in Cirsium sect. Eriolepis are discussed. The accepted names are: Cirsium echinatum, C. eriophorum subsp. eriophorum, C. eriophorum subsp. spathulatum, C. ferox, C. italicum, C. lacaitae, C. lobelii, C. morisianum, C. scabrum, C. tenoreanum, C. vallis-demonii subsp. vallis-demonii, C. vallis-demonii subsp. calabrum comb. nov., and C. vulgare (= C. crinitum, C. sylvaticum). Four accepted names are typified by specimens preserved at FI (one lectotype), G (one lectotype and one neotype), P (one lectotype), and by illustrations (two lectotypes). Several other heterotypic synonyms of taxa described from Italy are discussed and six of them are typified. A new combination and status are proposed: C. vallis-demonii subsp. calabrum, based on C. eriophorum var. vallis-demonii f. calabrum.

Typification and taxonomic remarks on five species names in Cytisus (Fabaceae).

This paper deals with the typification and taxonomy of five Mediterranean Cytisus species. Cytisus affinis, C. candidus, and C. spinescens nom. illeg., non Sieber ex Spreng. were described from Sicily by Karel Borivoj Presl, Cytisus spinescens was described from Apulia (southern Italy) by Curt Polycarp Joachim Sprengel, and C. villosus was described from southern France by Pierre André Pourret (1788). Lectotypes are here designated for Presl and Sprengel's names. A neotype is designated for C. villosus. The taxonomic revision of these five names confirmed that C. villosus Pourr. (= Cytisus affinis C.Presl) is the name to be used for the species occurring in the large part of the Mediterranean countries. Cytisus spinescens Sieber ex Spreng. (≡ C. candidus C.Presl = C. spinescens C.Presl, nom. illeg.) is the correct name for the amphi-adriatic species occurring in peninsular Italy, and along the NE coast of the Adriatic Sea. This species does not occur in Sicily and reference to this latter region in the protologues of both C. spinescens C.Presl and C. candidus C.Presl is a misinterpretation due, possibly, to exchange of labels.