I tested more and not only does a flower model not have the "origin" attachment point, it doesn't seem to have any attachment points. So, you can't put a Special Effect on it as long as it is that model, even with triggers, because there is no place to attach to it. Although, you can still create the special effect at the position of the unit, uses a point, not an attach point.
Ghan has said he has fixed this. Monovertex please confirm this fix. This was only a problem with people that had signatures in the upper levels like not the special members but the respected members.