|Laetiporus sulphureus - Sulphur Polypore On Robinia|
|This picture is from http://en.wikipedia.org/wiki/File:Climacodon_septentrionalis_134149.jpg|
see more pictures of Sulphur Polypore
To aid identification I have listed these two together as identification may be difficult from ground level especially if its a bright day.
The Climacodon septentrionalis has been inserted from wikipedia.org