I wish I had located this pattern before my St. Patrick's Day cards went out, but there is always next year. You can find the free pattern here.
This is not actually a bookmark pattern, but if you leave a long tail before you begin the starting chain you can extend the stem into a bookmark tail. My suggestion is to leave a much longer tail than you think you'll need. I found I needed to add thread as I ran out before I'd finished the length I wanted.
