Book  (1907)  Page(s) 125.  
 
1382. KONING, PROFESSEUR DE; P. moutan.
(1) 1899, L. Paillet's Cat.

Website/Catalog  (1903)  Page(s) 27.  
 
Pæonia Arborea (Tree Peonies)
The Tree Peony is really one of the finest plants available for the garden or the conservatory; it is quite hardy and does well under the simplest treatment. The smallest one will flourish in the most astonishing manner, bearing blossoms from 6 to 8 inches across, which will increase every year in beauty and size. In colors, the flowers range in great variety, from a white to a nearly reddish black. [...]
Price: Two-year old, named varieties, purchaser's selection, $1.25 each, $12.00 per dozen...
Professeur de Koning.

Website/Catalog  (1876)  Page(s) 26.  
 
Pivoines en Arbre.
231 Professeur de Koninck (Makoy)...5 fr.

Website/Catalog  (1876)  Page(s) 80.  
 
Paeonia arborea. Baumartige Paeonie.
Professeur de Koningk, violettrosa...2 50 M.

Website/Catalog  (1867)  Page(s) 21.  
 
Pivoines en Arbres (Pæonia).
Variétés Choisies.
231 Moutan Professeur de Koninck, pleine, rose violacé...5 fr.