1. A ‘key’ is the name given to a means of identifying plants and animals. It usually consists of a set of written descriptions which have a starting point which is very general and then the descriptions become more and more specific until the description can only fit one animal or plant. It is very difficult to find an example of a simple branched key. Most keys produced commercially cover a wide range of organisms and are very complicated.

In order to use a key, you must have a very good description of the animal or plant and have looked at it closely. Complex keys are more the province of the professional or academic botanist. Many children, and adults too for that matter, usually find it much easier to match a specimen of a whole, or part of a, plant to an illustration.

The teachers' sections of the Field Studies Council website are particularly helpful in this regard. See also "Resources" for this section.