Considering the history of the area which is now enclosed in the perimeter of the Natural Park of San Bartolo and how the site can still be considered as highly anthropized, for some visitors the enchanting richness of its flora comes quite as a surprise.
A recent study on the vascular flora revealed the presence of rare species throughout the territory of the protected area. The cliff zone, in particular, maintains some precious natural features and thus bears a number of species of great interest.
Heritage trees
By definition (Legge Forestale Regionale n.6 of 2005, Article 2, Paragraph 1, Letter L), heritage trees (in Italian “alberi monumentali”) are “trees of any species, rows or groups of trees or any plant formation which are of particular interest due to their cultural, historical, natural or landscape-related value, and which for age or size can be considered as rare examples of majesty and longevity or hold a reference to events or facts that are relevant from an historical, cultural or folkloric point of view”.
As a matter of fact, trees are silent witnesses of the passing of time and can often be linked to historical and cultural facts. Any information pertaining these plants further enriches the national and local heritage.
In 2000, a tree inventory was carried out. The study revealed the presence of as many as 376 specimens of “heritage tree” inside the park, representing 16 families and 28 species of extant plants.
Woodlands and forests
The original woodland areas have practically disappeared or reduced to small, impoverished patches. The presence of aggressively growing plant species, such as
Rubus bushes (among the indigenous species) and Robinia, Laurus and Ailanthus (among the non-indigenous ones), further exacerbates the process of impoverishment.
On the other side, some autochthonous trees and shrubs have become rare and can be found solely in the least disturbed areas of the park. Among these, some significant examples are: Austrian oak (Quercus cerris), European hornbeam (Carpinus betulus), common hazel (Corylus avellana), Italian maple in itsobtusatum subspieces (Acer opalus subsp. obtusatum), spurge-laurel (Daphne laureola), tree heath (Erica arborea), that is normally more common in non-coastal areas of the region and typical of mesophilic forests.
Other species that are worth mentioning are Clematis viticella, not very widespread throughout the region, Clematis flammula, a thermophilic species most common within the Mediterranean vegetation such as the one of Mount Conero, and Pistacia lentiscus, a very interesting legacy of the Mediterranean vegetation of which only scarce traces can now be found in this area. The outcrops of hard and compact arenaceous rocks are characterized by an arboreal prevalence of deciduous downy oaks (Quercus pubescens). In sectors where the soil moisture content is higher, instead, the vegetation is composed of small stands of white poplars and field elms.
In other sectors, such as near the towns of Santa Marina Alta and Fiorenzuola di Focara, stretches of coniferous woodland (e.g. Pinus nigra and Pinus halepensis) are found. These were planted decades ago to prevent hydrogeological phenomena and related risks.
Crops and herbaceous species
The dry grassy areas located on the crag, mostly towards the summit, showcase an interesting array of herbaceous species.
On the edges of cultivated fields, too, rare or uncommon herbaceous species can be found, such as Geranium tuberosum , Tulipa agenensis, Tulipa clusiana , Tulipa sylvestris and Urtica urens.
Fields that were once used to grow crops and uncultivated grassy areas that generally replace them today have a fairly homogeneous and common flora, even though some sporadic herbs such as Orobanche picridis and Vicia lutea or rare ones such as Fumaria parviflora are worth mentioning.
What is of greater interest are the dry grassy zones which can be observed on some of the main peaks, such as Mount Brisighella, on the steep slopes flanking the road or on the edges of the fields.
These highly fragmented environments are important areas of refuge for many species of orchids (e.g. Anacamptis pyramidalis, Anacamptis coriophora, Spiranthes spiralis, Neotinea tridentata, Ophrys apifera) and various thermophilic and  xerophilous species such as Galatella linosyris, Fumana thymifolia, Galium lucidum, Ononis reclinata, Silene nocturna, Valerianella coronata, Valerianella muricata and others. In sub-ruderal environments, among the numerous nitrophilous and invasive species, interesting specimens can be found, among which Veronica cymbalaria, a plant that is very rare in the whole region but found the conditions for its proliferation inside the perimeter of the park.
Beach vegetation
The coastline stretching at the foot of the cliff is mostly formed by a narrow strip of deposits, composed of gravel and pebbles. Depending on tide and weather, the sea level fluctuates and the foreshore can be covered by salt water, thus not being a suitable habitat for most plants. Where the positioning of submerged or emerged barriers has favored the deposit of sandy material, the shoreline presents some
patches of beach.
The most sheltered parts of the seaboard host a small number of plants which deserve to be noted, among which are Lotus maritimus and Crithmum maritimum.
Aristolochia clematitis and Solanum dulcamara grow in between the rocks of the cliff, even though they are quite infrequent.
In the small sandy beaches, visitors may encounter some psammophilous species which are now rare in the rest of the regional territory, such as Eryngium maritimum, Cakile maritima, Salsola tragus subsp. pontica, Limbarda crithmoides and the pretty bindweed Calystegia soldanella. At the southern end of the Natural Park of San Bartolo, the bay of Baia Flaminia is a vast sandy beach, very popular among locals and tourists and fully equipped with beach facilities and services. In the more consolidated lumps of this sandy shore, as if they were oblivious to the presence of human visitors and their facilities, a wide range of local vegetation thrives, among which a number of nitrophilous and ruderal species and some more uncommon and interesting species such as Hypochoeris radicata and, above all, the rare sedge Carex divisa