Alder (Alnus; Ukrainian: vilkha). A genus of deciduous trees or shrubs of the birch or Betulaceae family that have dark-green leaves and conelike seeds. The black or European alder (Alnus glutinosa), which attains a height of 25 m, is the most common species in Ukraine. The gray alder (A. incana) grows in the Carpathian Mountains and attains a height of 10 m. Alder wood is soft and reddens on contact with air. It is used for underwater construction, furniture, and veneer. The bark is used in tanning and paint-making. The tree grows in moist soil, particularly in Polisia, where it forms whole groves. The European green alder (A. viridis), which has small leaves similar to birch leaves and which attains a height of 2 m, grows in the subalpine belt together with the mountain pine.