You should read Vue EULA. I am sure that e-on software don\'t allow to distribute plant models from Vue. In case of their new plant edition software TPF, they even forbid to make public or sell any models you make from scratch, not to mention the models delivered with the software. But personally I have no problem with mine models available here :-)) When you export models form Vue, you should set in export settings option \"generate alphamaps\", because all models you have uploaded miss alphas, so they are unusable in current format. Check more about 3D plants creation on http://greengene.republika.pl/
I am happy you enjoy those models, but be aware that they may breach e-on copyrights. Those are models I have made some 8 years ago on behalf of e-on software using Botanica plant editor for Vue.
Now I am working on new 3D trees in the most advanced plant editor yet available - The Plant Factory. I have developed TPF editor with e-on for last 6 years. It is really good. You can try a free version of it. I invite you to visit my new website about 3D vegetation :