I googled 'beauty of Kashmir' and didn't find a flower. However, Google provided 23 pages of references with the exact phrase 'beauty of Kashmir.' There might be more than 23 pages if I had kept clicking.

It is clear that 'beauty of Kashmir' has become a set phrase, rather like 'gay Paree' or 'golden Prague.'

It still might be a flower, but if so, nobody seems to be selling it at present.