The Eisenhower Tree is left of Augusta's 17th fairway, 210 yards off the tee. Eisenhower hit the tree so often during his many rounds that he tried to convince other members the tree should be cut down.
According to Masters.com, the tournament's official Web site, "At a Club's governors meeting in 1956, Eisenhower proposed cutting the tree down. Clifford Roberts promptly ruled him out of order and adjourned the meeting."
At what specific point the tree came to be known as the Eisenhower Tree is not known, but a good guess is pretty soon after that meeting.
Calling it "the Eisenhower Tree" might have been inspired by the existence of another Eisenhower Tree: On Aug. 28, 1954, a pine tree, known as the Eisenhower Tree, was planted at Gettysburg National Park in Pennsylvania by members of the World Wars Tank Corps Association. Eisenhower commanded Camp Colt, on the Gettysburg battlefield, during World War I, and the tree was planted at the spot where Eisenhower's headquarters was situated. (That Eisenhower Tree was later killed by lightning.)
The tree rarely comes into play anymore for today's players at the Masters Tournament, but remains a nuisance for ordinary golfers.