| The Old West city of Tombstone, Ariz., is famous not just for the Gunfight at the O.K. Corral but also for the world's largest rose bush. The Lady Banksia Rose Bush was planted in the back of a boarding house in 1885. Today, more than century later, the rose bush (nicknamed the Shady Lady) is the world's largest - at last measurement, its canopy of white blossoms covers more than 8,000 square feet! Lee Cowan reports on a magnificent, and seemingly immortal, desert bloom.