This Psathyrella was growing under the Hawthorn - a fruitful place to search at the moment.
Perhaps Psathyrella vernalis. Vernal relates to spring, but if the plants are confused, why shouldn't the fungi be?
A few heads of Sharp-flowered Rush - Juncus acutiflorus - are still standing. They accumulate water quite nicely.
As do the leaves of the Scots Pine - Pinus sylvestris.