Book  (1966)  Page(s) 210.  
 
Count d'Orsay, a distinguished man of letters and a Director of Fine Arts during the Third Empire, was a great dandy....He generally wore a rose in his buttonhole, his favourite one being Rose d'Amour, which came to beknown, also, as Count d'Orsay's Button-hole Rose. 

Book  (1951)  Page(s) 230.  
 
...the pink Buttonhole Rose, with its sharp little pointed buds, also called Rose d'Orsay because that famous dandy affected it in his coat. I have never been able to find this in any nurseryman's catalogue.