The odd looking sticks or wooden clubs you sometimes see on the wall behind an Irish bar in North America are Shillelaghs or Irish fighting sticks. They come in many styles, with the type found behind bars, usually being a short club made from a forked section of a blackthorn, decorated with shamrocks. A more traditional style which can serve double duty as a short walking stick / fighting stick, has a pronounced rounded wooden knob on the top, often from the blackthorn root.
Hanging a scale miniature shillelagh on the wall or hearth, is a time honored way to show your Irish heritage, or decorate an Irish Pub. The two shown here are both made from twigs, painted to resemble the traditional blackthorn of Ireland.