Complex sentence: Most commonly found along rivers such as the Volga and Danube, it is one of very few elms tolerant of waterlogged, anoxic ground, its extensive shallow root system ultimately forming distinctive high buttresses around the base of the trunk.
Split into simpler sentences: Most commonly found along rivers such as the Volga and Danube, it is one of very few elms tolerant of waterlogged, anoxic ground. The extensive shallow root system ultimately forms distinctive high buttresses around the base of the trunk.