Website/Catalog  (1930)  Page(s) 24.  
 
Single Peonies.
The single varieties are becoming very popular as they become better known. They are more early in season and very attractive.
85 Black Prince. Thurlow. Dark garnet, not glossy. $3.00

Book  (1928)  Page(s) 85.  
 
Descriptive List of Chinese Peonies
Black Prince. (Thurlow, 1915.) 8.5.
Single type; large; midseason. Long, cupped petals, irregularly arranged, deep crimson with a dull, satin sheen; center small, stamens reddish at base, tipped yellow; carpels green with prominent white base and tips; fragrance not pleasing. Medium height; floriferous; stiff stems. Excellent foliage.
Generally considered an excellent single peony, and the erect habit of the plant is well adapted to garden decoration.
"The lateral buds give a continuation of bloom for two weeks or more and petals hold their color until they fall."—Thurlow.

Magazine  (Aug 1923)  Page(s) 269.  
 
"The American Peony Show at St. Paul" by Edward Auten, Jr.
...The Thurlows had a large and striking exhibit of singles and Japs, wonderfully fresh to have come so far. The outstanding kinds were Sophia Houston; Purity (Bunting); Eglantine, which was shown in most exquisite color; Black Prince, a fine deep red, with a good mass of yellow stamens, and green carpels which do not spoil the effect as the red ones do in so many varieties. 

Website/Catalog  (1916)  Page(s) 5.  
 
Single Herbaceous Peonies
Black Prince (Thurlow), a seedling of our own growing, very dark garnet with a mass of golden stamens, soft, rich coloring, not glossy. Not for sale.