Alnus incanca (L.) Moench supsp. incana
Deciduous tree or shrub up to 25 m. The species is widespread in Europe, from Scandinavia and northern Russia to Central Europe and the Balkan Peninsula. In Greece, the geographical range is limited to W Rodopi, where it occurs in five localities, at an altitude of over 1,000 m. The species usually grows along streams in moist areas, rich in nutrients. The area of occupancy of the subspecies in Greece is relatively small, <2,000 km2, mainly because of the specialized habitat that it occurs. It is included in the Red Data Book of Rare and Threatened Plants of Greece, in the category 'Near Threatened' mainly because of the limited distribution in Greece.