Book  (Oct 2001)  Page(s) 183-184.  Includes photo(s).
 
Clematis 'Evirida'
Trade name: Pistachio
(C. florida 'Evirida')
Raymond Evison (England)
Introduced by Guernsey Nursery in 1999
Sport of C. 'Evison'
... single, creamy white flowers... six broad yet pointed, overlapping tepals... Late flowers in autumn carry a greenish tinge to the tepals... a hard pruning [in early spring] results in the loss of early flowers... Requires a warm, sheltered position...