Scientists arent sure. Their best guess is that the plant was named after the way its runners strew, or scatter, around the mother plant.
But its name could also have come from the old Anglo-Saxon word for haystreawwhich was ready for harvest at the same time that the berries were ripe for plucking and eating.
Or, it could have gotten its name because of the way street vendors used to string the berries on straws of grass or hay to take to market.
Maybe theres some truth in all three guesses.