Book  (2005)  Page(s) 188.  
 
'Donau', hybrid wichurana. Syn. 'Graskae' [error: Breeder Praskac]. Parents unknown. 1913. Height: 5 to 6 m. Non-recurrent. Double, sun, hardy, tolerates poor soils.
The double flowers, opening, are initially magenta-pink, later become purple-violet. They form innumerable pyramidal trusses which bloom within small, medium abondant foliage. The shrub is vigorous and blooms late. It tolerates a light shade.

Book  (19 Apr 2000)  Page(s) 128.  
 
'Donau', LCl, 1913; Praskac

Book  (Apr 1999)  Page(s) 296.  
 
Donau! [Translation: "Danube!"] Wichuraiana, Praskac, 1913. 'Erinnerung an Brod' (Setigera) x 'Rubra' (Wichuraiana)... Reddish lilac tinted slaty blue... Violet red... clusters of fragrant purple-violet flowers which fade steely blue... a richer purple [than 'Veilchenblau']... The color varies according to the exposure and the nature of the soil... few thorns...

Book  (Nov 1994)  Page(s) 229.  
 
Donau Praskac (Czechoslovakia) 1913. 'Erinnerung an Brod' x a pink hybrid of Rosa wichuraiana... cerise-pink...

Book  (Mar 1994)  Page(s) 98.  
 
Donau almost identical to 'Veilchenblau', flowers a bit larger...

Website/Catalog  (1946)  Page(s) 34.  
 
H. W. [Hybride de Wichuraiana]. — DONAU (Graskae 1913). Petites fleurs lilas rouge&tre teinté bleu, passant au bleu ardoisé.

​​​​​​​[no longer listed in 1956]

Book  (1936)  Page(s) 213.  
 
Donau (HW) Praskač 1913; Erinnerung an Brod X R. Wich. rubra; reddish lilac, changes to reddish lilac-blue, fades to bright slaty blue, 5cm., very double, large clusters up to 30, fragrance 8/10 (lily of the valley scent), few thorns, glossy green foliage, growth 8/10, very climbing. Sangerhausen

Book  (1933)  Page(s) 172.  
 
DONAU. F. Praskac, 1913. An interesting mixture of Multiflora and Wichuraiana strains, bearing clusters of fragrant purple-violet flowers which fade steely blue.

Book  (1930)  Page(s) 394.  
 
Donau. (Praskac 1913). Bloom 4 to 5 cm across, quite full, passing from reddish lilac to slaty blue, strong and fine fragrance, in abundant trusses. Vigorous shrub and very willing to bloom.

Magazine  (Jun 1929)  Page(s) 71.  
 
Donau (Praskac, 1913), Trinnerung and Brod x Wichur., fleur grande, pleine, bleu d'ardoise avec lignes rougeâlres, passant au bleu d'acier.