Snake's head fritillary (Fritillaria meleagris) surprisingly is native to this country, due to its unusual bell-shaped flowers with checked pattern on shades of purple.

http://plantas-y-flores.blogspot.com/

There is also a very pale, almost white variety.  It is perfect for the  woodland garden thriving in moist conditions in partial shade although it can  also grow in full sun.  It is fully hardy and will grow to 30cm (1ft) tall.

Read more: http://www.thegardencentregroup.co.uk/plants-of-the-month/Fritillaria-meleagris/A6#ixzz1nsc1aYk0