Corresponding author: Lorenzo Peruzzi (
Academic editor: S. Bogdanovic
We present an updated list of the vascular flora occurring on Elba island (Tuscan Archipelago). The list is based on bibliographic analysis and field studies carried out in the years 2006–2018. With a total of 1,098 specific and subspecific taxa currently occurring on the island (including 101 naturalized aliens), plus 67 casual aliens and 16 hybrid taxa, Elba shows the highest number of species among the islands of the Tuscan Archipelago. Two taxa are new for Tuscany:
Carta A, Forbicioni L, Frangini G, Pierini B, Peruzzi L (2018) An updated inventory of the vascular flora of Elba island (Tuscan Archipelago, Italy). Italian Botanist 6: 1–22.
A flora is a useful source of information for biogeographical, ecological and evolutionary studies (
Particularly, islands have long served as an inspiration for evolutionary hypotheses because their biotic assemblages and ecological processes are clearly delimited by geographical constraints (
The Mediterranean Basin is recognised among the most altered hotspots of biological diversity worldwide (
The Tuscan Archipelago consists of seven islands and about twenty islets midway between mainland Italy and Corsica (France), and is one of the most interesting areas in the Central Mediterranean area from a naturalistic point of view (
Starting from the mid-1900s, several studies were devoted to the flora of the Elba island (
We searched all published papers dealing with plants on Elba island and extracted occurrence records for all those species reported for the island. Smaller islets around Elba island were not considered because their flora was already studied and published by
Besides the occurrence on the island, the collecting site was also recorded; localities reported on historical publications or herbarium labels were attributed to one or more of the identified operational geographic units (see below). Literature search was complemented by several field surveys carried out during the years 2006–2018 across the whole island; some sites (e.g., low altitude western slopes of Monte Capanne, Capoliveri mines) were visited multiple times during the same year, matching distinct flowering times across the seasons; other sites (e.g., Cala del Pisciatoio, Mola) were specifically visited to verify historical records or to explore under-sampled areas (as emerged from literature analyses). Our most relevant floristic findings were published during the research:
Nomenclature and circumscription of the taxa follow
The OGUs were identified based on bioclimatic (see
Localisaton of Elba island (red circle) in the Central Mediterranean area and subdivision of the island into 12 Operational Geographic Units. The numbers distinguish the western (
To assess whether observed frequencies of categorical variables (historical occurrence, taxonomic rank, chorology, and life form) differ significantly from theoretical expectations, we used χ2 tests. In addition, to determine whether there was a significant association between two categorical variables (among those listed above), we also applied a χ2 test of independence or simple multinomial logit model (for binary categories, namely confirmation). All analyses were performed with the software R (
A total of 1,098 specific and subspecific taxa currently occur on the island, including 101 naturalized aliens, representing about 9% of the flora, not considering casual aliens (67) and hybrid taxa (16);
Concerning the distribution of floristic diversity, while for 12 taxa a detailed distribution on the island is not available, 3b, 1c, and 2a show, respectively, 589, 546 and 540 taxa, and are the OGUs hosting the highest number of taxa. Floristic diversity is largely comparable among western (1), central (2) and eastern (3) portions of the island, but shows significant differences (p < 0.001) among ecological belts, with (d) and (e) being the poorest ecological belts, while (c), and especially (b), are the richest.
Considering the whole island, three families alone cover more than 30% of the total vascular flora (
Biological and chorological spectra highlight that therophytes (39%), hemicryptophytes (27%), and geophytes (15%) are the most represented life forms, while Mediterranean (47%), Euro-Mediterranean (24%), and Eurosiberian (11%) are the most frequent chorotypes. Alien taxa represent 6% of the total flora.
Italian endemics (
Further 19 taxa occurring on the island are of high phytogeographical interest:
Taxa confirmations are not equally distributed among life forms, chorotypes, and OGUs (Figs
Life form spectra for each Operational Geographic Unit. CH = Chamaephytes, G = Geophytes, H = Hemicryptophytes, HE = Helophytes, I = Idrophytes, NP = Nanophanerophytes, P = Phanerophytes, T = Therophytes.
Families are mostly equally distributed (p > 0.05) among sectors and belts. Life forms and chorotypes are however not equally distributed (p < 0.001) among families.
Life forms are significantly associated (p < 0.001) with chorotypes: Mediterranean taxa are mostly represented by therophytes (46%), and Eurosiberian taxa are mostly represented by hemicryptophytes (40%). Italian endemics are mostly hemicryptophytes (39%) and geophytes (34%), while alien taxa are mostly represented by phanerophytes and therophytes (more than 60% altogether).
Life forms are also significantly associated (p < 0.001) with OGUs (Fig.
Chorotypes are also significantly associated (p < 0.001) with the OGUs (Fig.
Chorological spectra for each Operational Geographic Unit. Alien = alien species, Endem = Italian endemic species, Extraholarctic = species showing range larger than Holarctic floristic kingdom, Eurosiberian = species showing range within the Eurosiberian floristic region, Eurosib-Medit = species showing range across Eurosiberian and Mediterranean floristic regions, Medit = species showing range within the Mediterranean floristic region.
With a total of 1,098 specific and subspecific taxa currently occurring on the island, Elba is confirmed as the island hosting the highest number of vascular taxa in the Tuscan Archipelago. This is mostly due to the larger extension of Elba compared to other islands (
The overall analysis of life forms and chorotypes revealed that the
Elba hosts around 80% of the flora of the entire Tuscan Archipelago (
The problem of alien species has already been highlighted by
The OGUs hosting the higher number of species (3b, 1c, 2a) are also the largest ones (Fig.
OGU 1e, besides hosting a flora with temperate features, also hosts the majority of Italian endemics, albeit a few endemics are however also occurring in coastal habitats (
In spite of the institution of the Tuscan Archipelago National Park, including several specific
We are grateful to friends of Acta Plantarum, Roberto Adamoli, Fabrizio Bartolucci, Mario Calbi, Leonardo Cocchi, Marco D’Antraccoli, Gloria Cortesi, Giovanni Gestri, Gianniantonio Domina, Michele and Rolando Galeazzi, Valerio Lazzeri, Mairo Mannocci, Dino Marchetti, Francesco Roma-Marzio, and Adriano Soldano for helping in the identification of some taxa and for providing useful information on localities and/or literature. Finally, Gianniantonio Domina and Gabriele Galasso are gratefully acknowledged for their careful reviews and useful suggestions.
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