Definitely ground-blue. Because sky-blue and the sea-blue cannot rival it.

Every spring, they turn the woodland floor into a carnival, swaying in their thousands in the rain and lobbing perfume into the air like so much confetti. The UK has about half the world’s bluebells, and considering that a sizeable bulk of them are crammed into the 2.5% of the country that is still ancient woodland – well, you get the idea. In early May, you cannot really tell if trees have roots or are just afloat on a fragrant sea.

Occasionally, their show adds a stichwort or two.

Or frames a passing fox.

England has an extremely rich plant folklore; even the most obscure flowers have acquired strange connotations over the centuries. Bluebells, upfront and demanding on the senses, stirred imaginations forcefully in their bell-like shape – they rang for fairies, so they said, but any humans who heard the tolling were doomed. More practically, their bulbs provided starch that stiffened Elizabethan collars and their sap deterred insects from attacking book binding.

Today, they have protection under the Wildlife and Countryside Act against commercial gatherers, although there is also concern that the introduced Spanish bluebell is hybridising where it escapes from gardens. But mostly the blue show goes on. And it is, as you can see, almost entirely blue, except for the odd moments when it is white.

Like white wave caps on the woodland sea.