Book  (Oct 2001)  Page(s) 104-105.  
 
Clematis albicoma
Herbaceous/Integrifolia Group
Origin: United States (Virginia and West Virginia)
Species
... single, solitary, nodding, urn-shaped flowers, composed of four tepals... The tepals, with a covering of silky hairs on the outside, are yellowish with a flush of bluish purple towards the base...