Definition of "marram"

Rather would we compare these marram-tufted, wind-sculptured sand-wastes with the Red Sea litoral and the Egyptian Soudan, where Osman Digna led British troops memorable dances in the ‘nineties—alike both in their physical aspect and in their climate, red-hot by day, yet apt to be deadly chilly after sundown.

1910, Walter John Buck, Abel Chapman, Unexplored Spain‎

He circled rapidly, stopped, swerved, and, at the canter, took up another scent. Suddenly, in a tussock of marram, his nose and he stopped dead.

1919, F. St. Mars, The Way of the Wild‎