Book  (1917)  Page(s) 89.  
 
Helene Leslie. Large white guard petals. Centre sulphur yellow. Odour of a rose. Barr. Crown. White and yellow. Large. Midseason. Fragrant. Tall, free bloomer. Strong grower. Garden and cutting.

Website/Catalog  (1909)  Page(s) 6.  
 
Double Herbaceous Peonies.
Helene Leslie. Primrose-yellow with large white guard petals, rose-scented...$1 25

Book  (1907)  Page(s) 132.  
 
1470. LASLIE, HELENE; P.
(1) 1899, Peter Barr & Son Cat., p. 46.
(2) 1906, Peter Barr's Cat., p. 69.

Magazine  (9 Apr 1904)  Page(s) 473.  
 
"Popularizing the Peony" by George C. Watson.
Among the June flowering I think I am fairly safe in mentioning the following:
White
Helene Leslie...

Website/Catalog  (1895)  Page(s) 22.  
 
Barr's Hardy Double Chinese Pæonies.
Whites.
Hélène Leslie, primrose and white, extra fine, 2/6. 

Website/Catalog  (1891)  Page(s) 21.  
 
Splendid Hardy Chinese Double Pæonies.
Whites.
Helene Leslie, opens blush-white, with primrose centre, rose-scented, extra-fine, 3s. 6d.