Book  (1917)  Page(s) 225.  
 
Anomala....Varieties: Insignis (remarkable). A form of this is grown in gardens under the name of Peter Barr. Flowers magenta.
 

Book  (1907)  Page(s) 3.  
 
Peonia Anomala, Linn. .... Its varieties, Insignis, Peter Barr, Smoutti and Intermedia are now recognized, being more distinct in the character of foliage than otherwise.