Too spiky to grab.James has found a number of these spiky seed pods since the heavy rains. They have been washed along so we haven't been able to find the source tree.
Some internet research has found that this is the sdeed pod of the castanea sativa (sweet chestnut) tree. This page shows what the tree looks like so now James can go exploring.
The spikes are VERY sharp which is why James' fingers are holding the ball so carefully.
Now that's going in the Treasure Table.