Currently I am working on a next release of my Space Tree Pro addon. One of the things it will feature is randomization of the basic ellipsoid crown shape and some additional bundled tree examples. The one shown below is has photo realistic hazel leaves and has is crown slightly randomized.

I know of course that hazel trees or bushes normaly don't grow in a prairie like environment :-)

Features that will probably make it into the next release:

• Randomized crown outline
• Randomzied shape, offset and distortion of the crown shape, making it easier to create unique but similar trees
• A better looking trunk mesh
• The possibility to remove random branches, adding character to trees
• Several new, ready to use example trees

This new revision will of course be free of charge for people who already bought the addon.