So its 88 polygons for a ball with paper slices. Sorry for being over-critical, I am in fact happy that someone finally made a start for making some decent tree-ish decoration. But the more I am happy about that, the more I want to see it getting done properly.

You know, in clonk it is not even possible to rotate the view, so the question is if it makes sense to use the standard method of modelling plants in video games (plus a green ball, this is not really standard). To have a model like this for a static object like that (which also is supposed to be all around the place) makes IMO only sense if it is animated. Otherwise, a sprite is just as good or probably even better.
If you want to do bushes, shrubs, trees etc. properly (as realtime model or not), you should first take a glance of how it is generally done nowadays. If you google for tree modelling tutorials you'll find hundreds of tutorials and (copyright-free) examples, many also covering low-poly tree modelling. What you could also do is to take a glance at other video games with good-looking graphics and see how it is done there. Since a tree or a bush is such a common model, you can also find many pre-done models that would fit our license and graphics style. (For example here)

Otherwise, I said that already, I am happy that someone got to making more decoration thingies :-)

Hmm, I'd have to agree with what newton said about using a sprite. Unless you add more detail than just cloned planes in a radial formation, this is probably the way to go.

If you look at the tree I've made (Tree_Coniferous), it is not symmetrical at all. By being asymmetrical, it can be rotated in-game, allowing 359 differently shaped coniferous trees from only one 3D model. Perhaps you could try this with a shrub?

Did I scare you away?