Not exactly gardening, as I need identification of a wild flower, rather
than one in the garden, but I'm sure you folk will know.

Just now, there is a huge proliferation of flowers on every roadside verge,
central reservation and railway embankment. They are about 18 inches tall,
and the flower looks like a big daisy, i.e. yellow centre and lots of little
white petals radiating out. What am I seeing and enjoying (until the
council's highways department come and cut them all down)?