Book  (Oct 2001)  Page(s) 146-147.  Includes photo(s).
 
Clematis 'Charissima'
Walter Pennell (England) 1961
Named in 1974 by Sheila Gilbert, an employee at the [Pennell and Sons] nursery
C. 'Nelly Moser' x C. 'Kathleen Wheeler'
... single, cerise-pink flowers... six to eight broad, overlapping tepals... Each tepal is distinguished by a deeper coloured central bar and delicate veining. Whitish pink filaments carry dark maroon anthers...