I don’t know what this plant is called. It might be barley grass, but I’m not sure. In any case, it's a common grass and can be found everywhere at this time of year as kids return to school. It may be only a weed, but every time I see it I'm reminded of my school days.
Boys of my generation found an odd use for it which I'm sure has died out as kids now have phones to play with. This only worked if you were wearing your uniform pullover, which were always woolen and made with a fairly tight knit. The trick was to hold your forearm horizontal in front of you and place a plucked seed head on it with the point facing away from you. Pinching a bit of pullover sleeve between thumb and index finger, you pulled the sleeve back like a bow string and let go, propelling the seed head forward like an arrow. I don't recall how far they used to fly, but I'm sure the distances were prodigious.
Needless to say the practice was strictly banned at school for the danger it posed to life and limb. However, we persisted in fighting running battles with our dangerous weapons, and I'm certain no-one was pierced through the heart by an errant projectile or lost an eye in the process. And I don't think I ever had to recharge the battery in my school pullover.