Using Blender's modifiers and procedural textures in Cycles I build up a branch of a coniferous to a total of over 95 million vertices using a single 400,000 vert model.
Using shape keys and modifiers to create the needles.
Seeing what can be done with materials
Seeing what can be done using the modifers
First prototype for branch
Branch base model
First iteration of branch, ~400,000 verts
Second iteration, 3^2 * 400,000 verts
Third iteration, 3^3 * 400,000 verts
Fourth iteration, 3^4 * 400,000 verts
Fifth iteration, 3^5 * 400,000 verts