The flowers of <i>Rosa sp</i>. Note: the filename gives a false indication of what this is, I don't know what this is, but it's not what people usually mean by 'dog rose' please see discussion page.
<a href="//commons.wikimedia.org/wiki/User:Elucidate" title="User:Elucidate">Elucidate</a>
CC BY 3.0
<span class="int-own-work" lang="en">Own work</span>