Book  (Oct 2001)  Page(s) 113-114.  Includes photo(s).
 
Clematis 'Anita'
Tangutica Group
Rinus Zwijnenburg (Netherlands) 1988
Parentage: Open-pollinated seed of C. potaninii var. fargesii with possibly C. tangutica
... flower buds are creamy yellow... single, pure white, semi-nodding flowers... four to six tepals. There is a prominent central boss of yellow stamens...