Source : Webster's Revised Unabridged Dictionary (1913)

Matweed \Mat"weed`\, n. (Bot.)
   A name of several maritime grasses, as the sea sand-reed
   ({Ammophila arundinacea}) which is used in Holland to bind
   the sand of the seacoast dikes (see {Beach grass}, under
   {Beach}); also, the {Lygeum Spartum}, a Mediterranean grass
   of similar habit.