The Snake's Head Fritillary is the county flower of Oxfordshire and indeed also the provincial flower of Uppland in Sweden where it is known as Kungsängen lily. These wonderful plants are now not so common in the wild but can still be found in wet grassland areas - which is why Oxfordshire plays host to several thriving populations along the Thames floodplain.
Apparently in the past there were often many fields - but with ground drained for agriculture, gravel extraction and development, the wild colonies are now few and far between.
Wikipedia say that "the Meadow of Magdalen College, Oxford, the village of Ducklington, Oxfordshire and the North Meadow National Nature Reserve, Wiltshire are some of the best locations to view this flower".
Iffley Meadows is apparently also a good place to see them but these photos are all from Duckington near Witney - the flowers are out now and this Sunday you can gain access to the field as part of their festival. If you are in the area like I was the Easter weekend then it is worth a visit...lovely.
They also sometimes get called the 'Checkered Lily', 'Chequered Daffodil', 'Lazarus Bell' and 'Leper Lily', referring to the bell shape of the flowers, similar to the bells carried by lepers in medieval times.
There are lots of cultivated forms but in my view none match the native wildflower for it's wonderful chequered pattern which really does have a reptilian look about it. They appear mostly in shades of purple overlaying pale silvery scales but there are also many, like at Duckington, that are coloured creamy-white - but when the light shines through them you will still see that even those ones have a pale chequered watermark.