According to iamhigher, the first has been the object of many researches for 4 centuries, consecrated in works extending to the whole of Italy (see flora) and to individual provinces and districts, and which have made known, as regards vascular plants, almost all species and varieties that grow there. Less studied and in-depth was the ecological and phytogeographic side, which have only been tackled with a modern criterion for a few decades, so that there remain many gaps to be filled and a large number of species, if the area is sufficiently known, the conditions are little known. in which they vegetate. A first geobotanical synthesis, which remained incomplete, was sketched by Filippo Parlatore (1878): the Prodrome of A. Fiori introduced in vol. I of the Analytical Flora of Italy (1908): we lack, however, an overall work, carried out with a rigorous and perfectly up-to-date method.
Overall, the number of Italian vascular vessels varies from 4 to 5000 and would be precisely 3877 (including the most widely cultivated and naturalized) according to Fiori’s Nuova Flora Analyitica d’Italia (1923-29), which is the latest accurate census: fluctuations depend on the different criteria that the authors have made of the species; very understanding was the one adopted by Fiori. On the other hand, it would be premature to fix the number of cellular plants, certainly very considerable, as can be deduced from what has been published up to now by Flora Italica cryptogama, but many remain to be discovered; less known is their distribution; therefore we will only give some occasional mention of them. The number of the former is an indication of an undoubted richness of the local flora not in proportion with the surface as emerges from the comparison, for example, with France and the Iberian Peninsula. But the latter and the Balkans surpass it for a more powerful individuality and originality, testified by the higher number of endemic species due to a lower decimation carried out by the Glacial, as will be said in its place.
Three fundamental climates (in the sense with which the word climate is understood by American and English phytogeographers) compete for domination of the peninsula and the islands: the Mediterranean one of maritime type, semi-arid and temperate, to which consortia mainly correspond to evergreens: the mountain one , full of humidity and ocean color, of which the beech forest is the most typical expression: finally the alpine, moreover, little known, and it is the climate that is characterized above the arboreal belt and very similar must be the one that reigns in the higher areas of the Apennines and the islands, which the Emberger has recently called the Mediterranean climate of high mountains , also including coniferous forests. Moreover, they offer a quantity of so to speak local forms due to the latitude, the proximity of the coast, the exposure of the slopes, the direction of the valleys and it is these local climates that, together with edaphic factors, have determined a large number of associations , the most extensive of which are designated by the name of formations; here we will review the main ones based on the vegetation areas.
The first area (leaving aside for now those covered by the waters) is the Mediterranean, also known as evergreen due to the large development of fruit trees, shrubs and trees with persistent leaves: they total a hundred species representing about 11% of its flora, compared to 386 (41.2%) of annual plants only; and the disproportion would increase if biennials and herbaceous perennials were included in the compto. Therefore, it is not the number that decides, but their widespread diffusion and the physiognomy they give to the coastal landscape or near the coast, in comparison with that of the areas behind them.
One of the most extensive and characteristic formations is the “Mediterranean maquis” made up of the association of mostly evergreen shrubs and suffrutics: such as cysts ( Cistus ), heather ( Erica ), phyllirae ( Phyllyrea ), wild olive ( Olea europaea oleaster ), myrtle ( Myrtus communis ), the mastic tree ( Pistacia lentiscus , often associated with the deciduous P. terebinthus ) , the strawberry tree ( Arbutus unedo ), three junipers, an euphorbia with an arborescent habit but without leaves in the drought season ( Euph . Dendroides), an abundant palm especially in Sardinia and Sicily, the only one indigenous to us ( Chamaerops humilis ), several labiates rich in essential oils such as rosemary, stecade ( Lavandula stoechas ), two thyme ( Thymus vulgaris and Th . capitatus ), some thorny legumes ( Calycotome , Genista sp .), some lianas such as Asparagus and Smilax. etc. The name of cisteto, ericeto, palmeto and the like indicate the dominance that some species assume; the maquis is low, with the prevalence of arbutus, Phoenician juniper, some phyllirae, with the mixing of laurel and wild olive as in some sectors of Sardinia and, where holm oak predominates, passes to high maquis, also called maquis- forest: a variant of the first is the garrigue (from the Provençal garigue) typical of calcareous soils. Numerous herbaceous plants (especially Graminaceae, Cariophyllaceae, Leguminosae, Labiate, Composted) often annual and, in sterile soils, reduced to the smallest size and accelerated flowering (the so-called early Mediterranean microflora) mix and fill the clearings with the shrubs. bulbous and tuberous (a total of 180 species) such as the Asphodelus and Narcissus which also spread in the interclosed or finitime formations of Prato, the Scilla maritima , the grass with large panicles Ampelodesmos tenax , gigantic Umbrelliferae ( Ferula , Thapsia ), Carduaceae thorny with showy inflorescences ( Onopordon, Cynara , Scolymus ), while numerous microphytes of the genera Juncus , Sagina , Montia , Tillaea live in the slightly damp beaches , together with Isoëtes with graminiform leaves.