|Ribwort seed heads. Fuji F11
Many years ago as a youth, in the rapidly receding past, we would use Ribwort seed heads in lieu of conkers; we would take it in turns to strike each others stalk to see if we could chop off its head (the Ribwort stalk that is).
Interestingly, Ribwort (Plantago lanceolata) is often referred to as a Plantain; which is also used to refer to Bananas :)
I suppose if I tried to introduce today's youth to the pleasures of Springtime conkers, they would probably reply with "is there an App for it?"