Botany is the study of plants and the way plants interact with the environement around them. In straightforward terms, Yes, Botany is of extreme importance for us as it teaches us a lot of different things about the nature. Without understanding botany, plantation would not be possible which would mean less effective farming and hence, a global famine.
Botany also helps scientists understand how various plants can be differentiated from one another both in terms of their genetic structure and other properties/functioning. It is indeed one interesting area of science and is specifically good for students having keen interest in plants.
