Dogwood perhaps?

[Michaelaw]

http://www.redzonefilms.com/pics3/the weed4.jpg

[Grant]

Dogwood ... nope! Try a wild rose hard to tell without seeing the leaves or without being there and but that would be my guess.

[Michaelaw]

So is weed! Now I have to call Monsanto hotline!

[JAS_Photo]

Very pretty capture!

[Hillbillygirl]

Very beautiful pic of what looks like, (have to agree with Grant), a Thimbleberry, which is part of Rosaceae family.
Can't see the leaves, or stalk, but the centre of flower looks same.