Book  (1940)  Page(s) 82.  
 
In "Progress in Thornless Roses," by Dr. Niels E. Hansen:
[describing a seedling he was evaluating] It is a seedling of Red Star, a red Hybrid Tea. The pollen used was my Pink Semi, a selection of the Rosa laxa Retz. which I brought from Semipalatinsk, west Siberia, in 1913.

Book  (1936)  Page(s) 658.  
 
Semi (wild rose) Prof Hansen 1927; white, occasionally light pink, small, single, hooked prickles, glossy red fruit, upright habit, 2 m. Altai and Sibiria (Semipalatinsk).

Book  (Jun 1929)  Page(s) 8-9.  Includes photo(s).
 
Fer the prairie Northwest, hardy rose stocks are a real problem. The rose Semi which I brought from Semipalatinsk, Siberia, may help. It was introduced last year as Semi; it is Rosa laxa, Retz, which I grew from seed collected on the dry steppes of Semipalatinsk, Siberia, on my 1913 tour. It grows very tall. We have p.Iants 8 feet high and fully 13 feet across. This interesting wild rose has been described under many synonyms. The present name is given to distinguish it from other importations. It is native of the Altai Mountains, central Siberia and extending westward to the Semipalatinsk region. It should not be confused with R laxa, Lindl., which is a variety of Semipalatinsk.