Spring Snowflakes (Leucojum vernum) and Summer Snowflakes (Leucojum aestivum) look very similar and in fact both flower in spring. They resemble giant Snowdrops and are available as bulbs in the autumn- particularly L. aestivum 'Gravetye Giant' the form selected from the wild by William Robinson the influential Victorian gardener. It is this variety that I have planted in my garden and (as seen above) in my father's garden.
 The Spring Snowflake is said to grow wild in Dorset and Somerset and the Summer Snowflake grows in great profusion on the banks of the River Loddon in Berkshire (below) where it is still known locally as the Loddon Lilly. [see entry dated 18th. April 2017]