we were given this tree as a sapling and told it was a flowering cherry but for the first time we have fruit whitch is a pod, the size of a cashew nut can you help i/d it please, we are concerned that the fruit may be toxic
your tree is a flowering cherry, but it has contracted a fungal disease which causes the fruit to develop as these cashew nut shaped hollow galls. The galls are called Pocket Plum galls and are caused by the fungus Taphrina padi
As this is a disease of the bird cherry, Prunus padus, I would suggest that is likely to be the species of your cherry.
The link I have given gives a bit of advice on control etc but I am sure there is more info out there should you want it...