Here are 2 Fritillary species that flower in April and May.  One is a wild flower, the other is a garden favourite. The Fritillary genus Fritillaria has over 100 species. It is in the Lily family.

Snake’s Head Fritillary Fritillaria meleagris is a wild flower native to Europe and western Asia.  It was cultivated as a garden ornamental in Tudor Britain but was not recorded growing wild until 1736. It normally grows  in damp meadows but elsewhere may have escaped from gardens. The common name ‘Snake’s Head’ refers to its snake-like drooping flower head.  The word ‘fritillary’ refers to the flower’s chess board pattern and is also used as the common name for a group of butterflies.  

Crown Imperial Fritillaria imperialis ‘Maxima Lutea’ is a cultivar commonly planted in gardens in Britain. It was introduced in the 16th century from Turkey where it is found in the same areas as the original species of Crown Imperial Fritillaria imperialis.

The Snake’s Head Fritillary flower, like all members of the Lily family, has 6 tepals, a term used when the sepals and petals look the same. The flower secretes nectar at the base of each tepal. The flower is visited by early-flying bumblebees in April and May.

The Crown Imperial flowers are protandrous (anthers shed pollen before the stigma is receptive) and have nectaries (at the base of the tepals). They are pollinated by bees and wasps and, in Britain, by Blue Tits and Great Tits. 

This flower has been opened up probably by a squirrel. The 3-lobed style is longer than the stamens and the stigma is receptive before the anthers release pollen. The bumblebee is its most effective pollinator. Flowers last 6 to 7 days. Pollen, carried by bees on their thorax, is deposited on the extended stigma. When the anthers release pollen, bees seeking nectar climb up the tepals and get pollen on their thorax and wings.

 A mixed group of purple and white fritillary in a damp woodland.