Website/Catalog  (1916)  Page(s) 5.  
 
Single Herbaceous Peonies
Dreadnought (Barr), crimson; extra fine. 75 cents each.

Book  (1907)  Page(s) 73.  
 
738. DREADNOUGHT; P. albiflora.
(1) 1899, Peter Barr & Son, Cat.
(2) Cornell Plot No. 1698.

Magazine  (7 Jul 1900)  Page(s) 709.  
 
The Paeonies.
Messrs. Barr & Sons, King Street, Covent Garden, London, W.C., and Long Ditton, Surrey, as growers of hardy plants, &c., have over two acres devoted to them. On Staurday, June 23rd, notes were made of a number of fine varieties which they largely cultivate in their nursery at the address just given. 
Singles.—The singles are varieties of Paeonia albiflora...
Dreadnought is a very fine glowing purple...