Polygala sp., possibly Polygala polygama.

Sorry about that. Here's the correct link Thank you for any help. http://tinypic.com?ref=11b3ngz" target="_blank"> http://tinypic.com?ref=2wbyjpg" target="_blank">

Is this plant growing wild or in a garden? It looks rather like sickle-leaf golden-aster (Pityopsis falcata, formerly known as Chrysopsis falcata). Its range is far to the northeast from Oklahoma, but it's occasionally planted in gardens. If it's not the golden-aster, then it's some other plant in the composite family. Because the family has a lot of species with yellow flowers, and they are often hard to identify, some people call them DYC's, which, in polite phrasing, stands for darned yellow composite.

I think #1 is a type of Ladies Thumb. White, insignificant flowers in a cluster... #2 is a Deptford Pink. Nice, delicate...will pop up wherever. #3 is Partridgeberry. #4 is Asiatic Dayflower. All four of these are "wildflowers," or "weeds," depending on who is looking at them! I would pull up #1...not much to look at. I have #2, and leave them in my garden...they are briefly pretty--don't do well as a cut flower, though. Some people pay money for #3--I think it's a pretty little groundcover. #4, well, that's up to you. I'm not sure how invasive they get...if they are taking up prime garden real estate, I'd yank 'em! Emily