Sugar is, then, very important to our civilization. But what exactly is it? Of course, most of us recognize sugar immediately as the sweet material which we put in coffee or cakes. This common form of sugar is from two plants: the sugar cane (a type of grass which grows to a height of 20 feet) and the sugar beet (which grows underground). But in fact there are many types of sugar, and the chemist recognizes hundreds of different varieties, each coming from a different source.