Near Armsworth Park, on a cycle ride to The Yew Tree at Lower Wield where we basked a little too long in the sun. Within a couple of minutes of setting off for home we were drenched, and sheltering beneath a large tree trying not to shiver!
My pancake lens couldn't cope as well as my usual one, but is much easier to manage on a bike.
I think it's a type of brassica catch-crop used for late summer & early winter feed for cattle and sheep.