Website/Catalog  (1908)  Page(s) 39.  
 
Pæonia Chinensis, Chinese Pæony. Japanese Single Varieties.
These single flowering varieties, with their large flowers, often six to seven inches across, are very showy. They form a distinct sub-group in this family.
Undine. Bright pink, darker shading.

Book  (1907)  Page(s) 216.  
 
2532. UNDINE; P.
(1) 1904, Harrison's Paeony Manual, p.53.
(2) Cornell Plot No. 1457.

Book  (1907)  Page(s) 49.  
 
Japanese Peonies....
Undine. Bright pink, with darker shading.

Book  (1904)  Page(s) 53.  
 
The Japanese Peonys.
The nomenclature of this whole family is in a chaotic state, and the Paeony Society is hard at work naming and classifying them. I append Henry Dreer's list:
Undine. Bright pink, with darker shading.

Website/Catalog  (1903)  Page(s) 24.  
 
Japanese Single-flowering Herbaceous Pæonies.
No other plant flowering at the same season can vie with the Single Pæony for beauty, and an established bed, when in full bloom, with the large, silky flowers measuring from 6 to 7 inches across, and appearing like immense single Roses, is simply gorgeous.
Undine. Bright pink with daker shading.

Website/Catalog  (1901)  Page(s) 169.  
 
Japanese Single-flowering Herbaceous Pæonies.
The collection of twelve sorts offered below were selected for us by a reliable Japanese house, and we are assured contains the finest varieties in cultivation. 35 cents each; $3.50 per dozen.
Undine. Light pink, striped with crimson.