It could be a Cardamine species but I don't know which ones you might get in your area. Where I live it would be Cardamine pratensis which I believe has naturalised in N America. For future reference it is best to include the leaves in pictures. They are often the deciding factor in an id. Also there is no indication of scale in the photo so I might be completely misinterpreting the size of those flowers. This post was edited by floral_uk on Fri, May 16, 14 at 15:14

Asclepias includes a number of different cultivars with a wide variety of leaf shapes and flowers of many different colors. Are you familiar with butterflyweed? That's an asclepias. I'm not sure how many asclepias have waxy leaves, but not all of them. At least some of the thoroughworts have opposite leaves.

Go to a photo-hosting site like photobucket.com. Open up a free account. Upload your picture(s). Under each picture is a line called HTML tag. Click that and it will say "copied". Come back here and paste it in this message. When you preview your message, you should see the picture, then click submit.

100% sure it's cosmos bipinatus.They bloom in white and magenta also.You can collect the seeds and plant again next year.