The Fifth Division is not listed on the Confederate Order of Battle at Willson’s Creek, see:

The following Confederate States Army units and commanders fought in the Battle of Wilson's Creek of the American Civil War, fought on August 10, 1861 near Springfield, Missouri. Though identified with the Confederates, the Missouri State Guard were technically an independent army, as Missouri had not yet seceded, and were not folded into the Confederate Army of the West until March 17, 1862.

Second Division
BG James S. Rains

Infantry Brigade
Col Richard Hanson Weightman (k)

1st Missouri State Guard Infantry
2nd Missouri State Guard Infantry
3rd Missouri State Guard Infantry
4th Missouri State Guard Infantry
http://en.wikipedia.org/wiki/Wilson
%27s_Creek_Confederate_order_of_battle