The Wild Daffodil (Narcissus pseudonarcissus) has a widespread though sporadic distribution through England and Wales with strongholds in certain areas like the Lake District. Mysteriously it flourishes in such locales but not in others which should be equally suitable as habitats.
 The photograph above was taken in Lesnes Abbey Wood in South East London a couple of years ago. This fragment of an ancient landscape has long since been surrounded and cut off by the expansion of London yet retains large populations of Wild Daffodils, Wood Anemones and Bluebells. [See entry dated 16th. March 2018]
 I haven't really succeeded in naturalising N. pseudonarcissus in the garden but there is another wildling that does better:

 This is the Tenby Daffodil, sometimes called Narcissus obvallaris and latterly Narcissus pseudonarcissus subsp. obvallaris. It was endemic to the Tenby region of South Wales before entering mass cultivation. If it is a sub-species it looks rather different and it's unclear why it was particular to one part of the country.  
  There are other variations of the Wild Daffodil -which is also found on the continent- and I have yet to read a definitive explanation of whether it is one or several species.

 Growing nearby I have Narcissus Telamonius Plenus which may be a double form of N. pseudonarcissus (a rather shaggy one at that). I bought a handful from Shipton Bulbs in Wales. If I may quote from their catalogue:
 "These daffodils appear in woodlands all over Britain... They are nowadays associated with the very old variety N. Van Sion, introduced in the 17th. Century but the forms inhabiting our British woods and gardens are much smaller and wilder looking than the Van Sion offered by Dutch growers today".
 If Telemonius Plenus aka Van Sion is a relative of N. pseudonarcissus it looks closer to the Tenby Daffodil than the Wild Daffodil. Daffodil DNA seems to be somewhat obscure.