Strainer Fungus

The rotting centres at the top of fencing strainers and stobs often play host to plants such as grasses, brambles and tree seedlings, but the strainer at the corner by the Ferry Stores....

....is growing a magnificent toadstool.

It looks a bit like a giant funnel, Leucopaxillus giganteus, but that is usually found on the ground and appears in late autumn. An identification would be helpful as, if it's edible, I think I know someone who might be finding it on his breakfast plate.