These are deciduous trees, whose sizes vary from those of a shrub (Acer palmatum), to those of large trees, such as the Acer pseudoplatanus. The seeds are winged and united in pairs. The gems are opposite and this characteristic is what differentiates substantially, as regards the morphology, these plants from those belonging to the genus Platanus. The flowers are very inconspicuous. Depending on the circumstances, the A. are cultivated for timber (in many precious species), for the foliage that in autumn is often covered with beautiful colors, and sometimes for the bark, which reminds the skin of a snake.
the Aceraceae family finds its maximum diffusion in North America, where there is a large number of species. In Italy, six Acer live in the spontaneous state: A. campestre, A. lobelii, A. monspessulanum, A. opalus, A. platanoides and Acer pseudoplatanus. These are distinguished from each other, for the leaves that, in our species, are always palmata-lobed, for the size, for the habit and also for the habitat. It is particularly suitable for this use because it bears well the pruning, very heavy, which is subjected to its foliage not to overshadow the screw. It is a plant of mediocre dimensions, which, in general, is not used by us for ornamental purposes. It is a large tree, with fine wood, which prefers fresh areas; It has no practical importance from an ornamental point of view, while it has a certain value in the field of silviculture due to the characteristics of the rather precious wood; there. platanoides (curly maple) is a typical species of continental cold climates, reaching the Scandinavian peninsula to the north. It is a beautiful tree, with leaves of a beautiful green 5-lobed, ending in characteristically sharp points. It is used as an ornamental plant, for the elegant posture and for the beautiful color that the leaves take before falling in autumn; A. pseudo-platanus (mountain maple) is the largest Italian A., reaching in some cases even 40 meters in height. It is more southern than the previous one. In our country vegetates, as the Italian name clearly says, in the mountainous areas and mostly in the beech woods. It is widely used for ornamental purposes, both in the gardens, in the parks, and in the trees of the cities, with the exception of those with a distinctly Mediterranean climate. Today it is not common to find large A. in the woods, because the wood, very valuable, has been intensely exploited and those few remaining specimens are worthy of the maximum protection. Among the species introduced in Italy for ornamental purposes, especially the A. negundo, originating in the eastern part of North America, with leaves characteristically composed of five leaflets. We often use varieties with elegantly variegated leaves. A is also often used. saccharinum, also native to the eastern part of North America, much appreciated for the leaves elegantly engraved, silvered on the lower page and which, in autumn, take on a beautiful yellow color.
Cultivation of Acer:
the most valuable A. prefer fresh, fertile and deep soils, where they take on a good bearing and a straight and cylindrical stem. For multiplication, it is preferable to sow in seedbeds, where the plans remain two years.