One last point that people should recognize is that the identification of plants is an ongoing process, and that plant taxonomy is neither absolute nor fixed, but merely reflects the current state of our knowledge. The ancients attempted to relate types of plants based on what were then the most visible and obvious characteristics. Without microscopes, the smaller features of plant physiology were unknown to them. As our ability to discern smaller and smaller structures has increased, naturally we can get a better idea of what plants are related to what other plants. But the advent of the electron microscope and even more the rise of genetic analysis will no doubt show us many new things and cause many plant relationships to be altered. It is indeed ironic that we are facing a future in which our knowledge and our ability to gain knowledge will have have become so great that we will no longer be able to definitively identify the species of a plant in the field or even under a laboratory microscope.