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.
[1913 Webster]