Lightroom :: Sort Images In A Collection Set

I'm using nested Collection Sets and Collections in LR 3.4 to manage image selections for a large book project. I'd like to create web galleries from groups of images (a Collection Set) to share with others working on the project.
 
Is there a way to have LR sort the images in a Collection Set (all lower level sets and collections) by the collection and/or set name? When I display the top level Collection Set all the images show up sorted by file name. I can change that to any of the sort options under View | Sort but none of those are at all useful.
 
Here's the tree structure of part of the Collection Set (these are all Latin plant names):
 
Rosaceae                          [collection set]
   |
   --- Rubus                      [collection set]
   |     |
   |     --- Rubus arcticus       [collection]
   |     --- Rubus armeniacus     [collection]
   |     --- Rubus chamaemorus    [collection]
   |     --- Rubus idaeus         [collection]
   |     ---     etc.
   --- Sorbus                     [collection set]
         |
         --- Sorbus acuparia      [colleciton]
         --- Sorbus scopulina     [collection]
         --- Sorbus sitchensis    [collection]
 
I'd like to sort all the Rubus images together, in named sequence by Collection, and then within each Collection sorted by file name. Then all the Sorbus, etc.
 
Am I missing something in how Collections work? Is there a way to sort within a Collection Set as I need to?