Book  (Jan 2000)  Page(s) 235.  
 
Black Panther Hybrid Tree Peony. Saunders 1948. A semi-double red hybrid

Book  (Jan 1999)  Page(s) 210.  
 
Black Panther Tree Peony. Saunders (USA) 1948. Semi-double red... Large, shaggy mahogany-red flowers... Increases by underground stolons...

Magazine  (Sep 1977)  Page(s) 19.  
 
"Botanical Descriptions of 40 Saunders Lutea Hybrids" by Dr. David Reath and Silvia Saunders
...These descriptions aim to provide the nurseryman and the average gardener with a means of determining the differences between the hybrids, many of which are very similar indeed...
Black Panther—Almost fully double; ruffled, very "black" maroon petals. Flares lighter colored. Filaments red; uneven lengths. Stigmas crimson-pink; sheath very dark and small. Foliage narrowly cut. The stoloniferous habit soon makes a wide bush.

Article (magazine)  (Jan 1955)  Page(s) 25.  
 
Varieties Raised in America. All by Professor Saunders...
The "Black Pirate Group." Crimson to very dark, almost black maroon, single to double...
'Black Panther,' (1948)

Article (magazine)  (Jan 1955)  Page(s) 56.  
 
Alphabetical Check List of Tree Peony Names In  Public Collections And/or Available in Nurseries 1954-1955
Lutea hybrid, Crimson, 'Black Panther', (Saund. 1948), [Gardens] Scott Foundation