Selecting from a "pool" of Resources/Assets (Textures)

I've been reviewing the tutorials and API documentation but can't find any way to, from within a script, navigate or traverse the Assets found in the Resources pane of the editor. It feels like this should be possible?

If I have a layout like what's shown below in my Resources panel, is there a way to get access to the "Items" subfolder and/or its children as an Array of object/texture references from my scripting?

> Scripts

> Meshes

V Textures

|---- txClosed

|---- txOpen

|---- V Items

      |---- txGlove

      |---- txHammer

      |---- (~50 more textures here)

I want that pool of textures so I can randomly select one for assigning to an Image that is the contents of a treasure chest for a surprise item.