Book  (Oct 2001)  Page(s) 126.  Includes photo(s).
 
Clematis 'Benedictus'
Magnus Johnson (Sweden)
Named in honour of his son-in-law
Open pollinated seedling of C. 'Nelly Moser'
... single, large flowers... six or seven tepals... On opening, the flowers are light lilac, changing to almost pure white with age. Flat, white filaments with greenish and purple tinge carry reddish purple-violet anthers...