Book  (Oct 2001)  Page(s) 133-134.  Includes photo(s).
 
Clematis 'Blue Ravine'
Conrad Eriandson (Canada) c. 1978
Open-pollinated hybrid believed to be C. 'Nelly Moser' x C. 'Ramona'
... single, soft violet flowers... seven or eight wavy-edged tepals, each carrying a slightly deep violet central bar with veins radiating from it. Dark purple-red stamens have white styles in the centre... Prefers a sheltered position in sun or partial shade...

Book  (Apr 1998)  Page(s) 126-127.