Article (website)  (2014)  
 
1062 ornamentals flower (rose), Rosa sp., Pink hat, USA 1960, Gamma rays terminal buds (Unnamed floribunda) two-tone pink flower colour dramatic increase in floriferouseness almost immune to mildew MBNL 31

Book  (Apr 1993)  Page(s) 452.  
 
Pink Hat Floribunda, light pink, center deep pink, 1980, Radiation induced sport of Floribunda seedling; James, John. Description.

Book  (1988)  Page(s) 198.  
 
James (1983) reports on two induced mutants, 'Paula' from 'Queen Elizabeth' and 'Pink Hat' from an unnamed R. floribunda. Both were obtained as early as the fifties by γ-irradiation of actively growing terminal buds..

Book  (1988)  Page(s) 200.  
 
Table 26: Commercial mutants of roses
Pink Hat, U.S.A., +/- 1960, Terminal buds, γ-rays (Unnamed floribunda), Two-tone pink flower colour; dramatic increase in floriferousness; almost immune to mildew