Book  (2018)  Page(s) 155.  
 
Christen won the silver medal at a show in Paris in 1892 for displaying twenty-five varieties of clematis. He also entered shows in other parts of the country, such as the one held by Lyon Horticole in Lyon, where he displayed Clematis 'Papa Christen', 'Madame Boselli', and 'Eugene Delattre'.

Website/Catalog  (1924)  Page(s) 107.  
 
Papa Christen (Lanuginosa). Blanc rosé veiné foncé.

Website/Catalog  (1912)  Page(s) 78.  
 
Summer and Autumn Clematis.
In bloom from July to October.
These flower upon the wood of the current year's growth, and should therefore be pruned to five or six eyes.  
Papa Christen, delicate mauve, with a broad band of deep mauve down the centre of each petal; good...  2s. 0d.