Here's a variety of the things - not to be confused with banana relatives.

ribwort plantain

To shoot with them, you pick a flower stalk, and use the lower part of the stem to make a tight loop just under the head. Then, pulling the rest of the stem sharply against the firmly held loop, the head pops off with some force and goes a few feet, allowing it to be used to hit other children. Or teachers from behind. Or anyone really.

Penny