By Seo
South Yorkshire,
United Kingdom 
I have 1m high upright plant, self set, with leaves not dissimilar to marrow,cucumber or pumpkin. It has White trumpet like flowers which open and close with the sun. The "fruit" looks like a very small sweet chestnut to begin but develops and has a hard spiky outer shell the size and similarity to a large conker. Currently there are 15+"fruits"
15 Sep, 2012
Sounds to me like a datura or brugmansia. Not sure which, but i think that both plants are toxic. attractive flowers.
16 Sep, 2012