Here it is, a day late:
Walker Evans again, and I think a fine example of the kind of flexibility he had. This is a documentary photograph, showing soil erosion. Classic FSA stuff, "see, the soil is eroding, we need to increase our budget and do more things!" However, he's handled it as a fine piece of landscape art, he's found this fantastic tree and placed it in the frame just so, right in the right place relative to the rather photogenic eroded soil.
Erosion near Jackson, Mississippi. Shot by Walker Evans, March 1936.