Magazine  (Sep 1977)  Page(s) 22.  
 
"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...
Summer Night—Very single; 12 petals, dusky crimson. Flares dark; filaments uneven lengths, crimson. Anthers "naked". Stigmas many, warm yellow, sheath crimson. Foliage bronzy.

Article (magazine)  (Jan 1955)  Page(s) 25.  
 
Varieties Raised in America. All by Professor Saunders...
The "Banquet Group." Generally reddish, but with yellow undertone, single to double...
'Summer Night,' (1949)

Magazine  (Mar 1954)  Page(s) 22.  
 
Hybrid Tree Peonies
...By far the most important work with these hybrids has been done by Prof. A. P. Saunders and his originations now number about 80. Their color range is truly remarkable. [...]
The list of hybrid tree peonies following is up to date as far as we could make it.
Originations of A. P. Saunders, Clinton, N.Y.
Hybrids of suggruticosa, lutea and Delavayi.
Summer Night, Semi-double, dusky dark rose. 1949.