Last year I planted some dahlias (not sure on the type as they came from Big Lots). A few days ago as I was pulling weeds, I noticed these little things popping up between my two main dahlia plants. I pulled a couple up before I thought that it might be a little dahlia sprouting up. Are these little dahlia plants or something else? In this section of my garden, I have dahlias, day lilies, hydrangea, boxwoods, and I think a holly bush (or some prickly type of bush). I hadn't seen any other type of weed or vine sprouting out that looked similar to this in the past, but of course it could have spread here. Thanks for the help.