Original: Eucalyptus regnans , known variously by the common names Mountain Ash , Victorian Ash , Swamp Gum , Tasmanian Oak or Stringy Gum , is a species of Eucalyptus native to southeastern Australia , in Tasmania and Victoria .
Simplified: It is an evergreen tree , the tallest eucalyptus tree , growing 70-120 m ( 230-400 feet ) tall .