I found a list of pictures for your reference, so that you can match it to the your bush...http://ttiitn.com/artemisia/
Come to think of it, the bush he is sitting in looks like the first one, "ARTEMISIA ABROTANUM." Dr. Christopher talks about it here as being helpful for worms in children: http://online.snh.cc/files/2100/HTML/snh_southernwood.htm