I am afraid that what you have is Mugwort. If you only have a few, dig them out, try to get all the roots, they are very long, and every single little piece will grow a new plant. I had them after my house was renovated. The Koreans eat them when they just grow back in Spring. The previous owner of my house had a Korean wife. Maybe she planted them. They very quickly spread through the whole back yard, literally wall to wall mugwort. It was awful. I had then a professional gardener neighbor and he tried to help me get rid of them with Roundup, thinking that I did not spray correctly. Then he and his wife moved away, mugworts were still there. I then did research on the Internet and finally found that Lontrel (clopyralid) had successfully killed them in someone's else's garden. I was desperate. I really do not like to use herbicide, was trying to dig them out before I tried to spray with Roundup. At that time only professional gardeners could buy it. Fortunately I belong to a local garden club and someone helped me buy it. Very expensive. I think I paid $200.00 for it for 1 quart (the smallest size available). I wore a mask on my face, (wore goggles and breathing apparatus) and wore protective gloves and clothing and also some kind of socks over my shoes. Very early in the morning, when no wind was blowing, I sprayed very carefully on the leaves. Lontrel killed all of them. Amazing. Just one application. When I dug to plant my roses, I saw the roots of the mugworts, all black. Amazing. Mugwort is also known for herbal medicine. When I went to China in 2010, I saw them there too! So some people like them, for food (soup, etc., also for tea)-----
