If you know or try to guess the class or family of the plant, such as cacti, succulent, grass, tree, or bush and you know where it is native, or not. The internet can be a wonderful source of information leading to proper identification. Google and other meta-search engines can connect you with experts in just about anything. Colleges and universities often have horticulture and agriculture departments that run public offices whose purposes often include answering questions. It is true that having a digital camera can speed this process up, they can also show you images with which you can use to help I.D. your material too. With the internet and a little practice a great many things are possible. For example, there are even web sites about Sphagnum species which are complete with diagrams and photographs.