Cluster of brown fungal bodies, maybe 6 cm in diameter, spiny
Caution: Do NOT use iSpot to identify fungi to eat!
Some fungi are very poisonous so a mistaken ID could have serious consequences.
No interactions present.
Did you distrub these at all? They look to me as though they might not be puffballs at all but something like Lepiota hystrix or aspera.
I have picked one, left the others, and cut it open. Having looked at the photo on Wikipedia, I think you might be right Flaxton.
This is a close-up of the outside: http://www.flickr.com/photos/fluffymuppet/6168919665
The inside is plain white, but it did look like it might open into a cap:
Lat/Lng: 51.6, -1.3
OS grid ref: SU4998