Book  (Nov 1994)  Page(s) 230.  
 
Some authors [incorrectly say the rose called 'Flora' is] synonymous with 'William's Evergreen' which was a blush-white rose (1855)

Book  (1988)  Page(s) 84, 85.  Includes photo(s).
 
William's Evergreen...Growth up to 4 m. Once-flowering. Similar to 'Flora'...but with creamy-white flowers...

Book  (1936)  Page(s) 758.  
 
William's Evergreen (sempervirens) William 1855; R. sempervirens X ? ; white, center flesh-pink, medium size, once-blooming, many prickles, growth 9/10, climbs fast, 4 m, very hardy. Sangerhausen

Magazine  (Jun 1929)  Page(s) 73.  
 
Multiflores sarmenteux ...William's Evergreen (William, 1855), fleur moyenne, pleine, blanc, à centre rose incarnat, feuilles presque persistantes.

Website/Catalog  (1925)  Page(s) 11.  
 
William's Evergreen, white with flesh-coloured center

Book  (1924)  Page(s) 100.  
 
Rosa sempervirens is more susceptible from its nature. Well known are the sorts Félicité Perpétue and William's Evergreen. These form an inpenetrable tracery, a joy for nesting birds. One should pay attention to them in Parks everywhere where it is possible to lay out true bird protection groves.

Website/Catalog  (1914)  Page(s) 5.  
 
Williams Evergreen (sempervirens), medium-size, double, white with pink, very beautiful

Magazine  (19 Aug 1911)  Page(s) 404.  
 
The Parentage of Roses.
The following list of the world's Roses and their parentage has been compiled by Mr. Robert Daniel, 38 Russell Road. Fishponds, Bristol, and by his kind permission we are enabled to publish it...
William's Evergreen... S.V., William, 1850, White Ayrshire X R. indica flavescens

NB: No explanation is given for the abbreviation "S.V."

Magazine  (Jun 1910)  Page(s) 239-240.  
 
A l’Ecole d’horticulture de l’Etat, à Gand, tous les montants des contre-espaliers sont garnis de Rosiers sarmenteux qui produisent un très bon effet et enlèvent aux charpentes en fer beaucoup de leur raideur. M. Burvenich père, qui a publié ce renseignement en 1891 dans le Bulletin d’arboriculture, de floriculture et de culture potagère, à propos de la Rose Félicité-Perpétue signalait comme Rosiers sarmenteux recommandables : Belle de Baltimore, Bijou de Lyon, William’s Evergrem, Bijou des prairies, Eva Corinne, Laure Bavoust, Madame Sancy de Parabère, de la Grifferaie et Ornement des Bosquets.

Book  (1910)  Page(s) 111.  
 
The best roses regarding hardiness...Evergreen Roses: Félicité et Perpetué, Williams Evergreen.