Elm – tree-long-liver reaches a diameter of 3 meters and a height up to 40 meters. Scientists believe that the name of the lineage ilms (Ulmaceae) originates from the Celtic name alm – elm. A trait of elm wood to resist decay at a constant moisture was used in medieval Europe, where water pipes were made of tree trunks, hollowed out from the inside. It was also used for piers construction of the first London Bridge. Many cabinetmakers acknowledge elm as the most beautiful of European species of trees.