Galanthus nivalis  'Genainville' 
15th January 2015  
A double form of G. nivalis selected by Jean-Michel Groult for its regularity, 
I assume it came from Genainville in northern France.
References:
Bishop, M., A.Davis and J.Grimshaw. Snowdrops, A monograph on cultivated Galanthus. Griffin Press Publishing ltd. 2001 (reprinted 2006).
Davis, A.P. The Genus Galanthus.The Royal Botanic Gardens Kew/Timber Press.1999
Stern, F.C. Snowdrops and Snowflakes. The Royal Horticultural Society.1956.