Oh, Root of Jesse. I've always liked the Tree imagery associated with our Lord. This line has become part of the hymn O, Come, O, Come, Emmanuel. There is also an old Christmas song called, Christ, the Apple Tree, and the liturgy gets a good deal of mileage out of the idea that "He who conquered by a tree, on a tree was conquered." (In other words, the Devil caused the fall of the Human race, by tempting with the fruit of the forbidden tree, and Christ, in turn, conquered the Devil by His death on the Cross.)
I seriously considered doing an elaborate, celtic-knotty tree for this, but ultimately decided on a simple, and slightly Tolkienesque one instead. I also considered posting a polyphonic version of the Antiphon, but I really like the chant, so chant it is:
And, as usual, for those of you who are interested in knowing more about this particular Antiphon, I provide this link here.