In the Park there are centuries-old pinewoods, woods of beech and mountain maple, mixed woodland with incredible varieties of species which in autumn create a rainbow splash of colour: beeches, maples (5 different species!) ash, elm, lime and the rare yew and holly.
A large part of the Park is covered in woodland, which becomes age-old forest in the over 5,000 hectares (over 12,000 acres) of the Casentino Forests and in the forest around the Franciscan sanctuary of La Verna.
In addition to the vegetation found on the mountain belt, all types of woodland of the lower sub-mountain belt are well-represented; woods dominated by the black hornbeams, turkey oaks and sessile oaks, chestnut woods (especially in the Camaldoli area and at Castagno d’Andrea on the Florentine side), and reforestations of black pine. The rare cork oak is notable among the trees here, and in warm, rocky places there are some remaining examples of holm oak. But the Flora consists above all of herbaceous species, with over 1000 species recorded up to now, of which only 48 are trees and shrubs. The most valuable collection is to be found in the Mount Falco-Falterona massif.
In the meadows and glades and above all among the crags and on the grassy ledges of this mountain the record of thousands of years of natural evolution is preserved. Among species to be noted are the narcissus anemone (Anemone narcissiflora), purple saxifrage (Saxifraga oppositifolia), red bilberry (Vaccinium vitis-idaea), all of which are restricted to high mountains and area record of the ice-age of over 20,000 years ago. The Eugenia violet (Viola eugeniae), symbol of Italian flora which typically grows in the Apennine massif of central Italy, reaches its northern limit of distribution here. To these may be added other species of great interest for naturalists: the alpine saxifrage (Saxifraga paniculata), the black bilberry (Vaccinium myrtillus) and the mossy saxifrage ”Peter Pan” (Saxifraga moschata).
Lovers of mountain forest flora should not miss the spring flowering (April-May) of cardamines, snowdrops, scilla and corydalis which flower at the foot of the best-conserved beech trees, before the new foliage leaves unfurl, blocking out the light from the woodland floor. The best places to learn about and study the flora of the Park are the Valbonella Botanical Gardens at Corniolo (S.Sofia) and the Siemoni arboretum at Badia Prataglia. In the former, the main vegetation environments of the Tuscan-Romagna Apennines are presented, with over 400 species identified with signs, and three thematic itineraries have been organized.
The Siemoni Arboretum originated in the 19th century as a park garden where the famous forestry engineer, Carlo Siemoni, called on by the Grand Duke to save the forest, planted and acclimatised various exotic species of tree.
Some of these patriarchs are still living in the forest and, after 150 years, are a monument to the work of Siemoni.