Hypnum..

..moss is a curious name, and as I had never heard of moss being used as medicine (except sea moss which is really algae) I had to look up the origin. According to Wikipedia "It was formerly used as a filling for pillows and mattresses; the association with sleep is the origin of the genus name Hypnum (from Greek Hypnos)."
Maybe it is time for me to change the filling of my organic spelt pillow!