Build a feature tree with set of product decriptions

I have a product with set of descriptors, these descriptors are nothing but sentences which describe that product. I would like to extract useful keywords from those [login to view URL] first I would like to cluster these product descriptors into set of similarly grouped. Then after that from each cluster I would like to extract useful keywords from it. At the end we will end up with clusters with similarly grouped senetnces and from them we would have extracted useful keywords which explains these sentences in one word.