Psamma
(from psammos, sand; alluding to the use to which the species are put). Marrem Grass. ORD. Gramineae. A small genus (two species) of hardy grasses, inhabiting the shores of Europe (Britain) and North Africa. Spikelets in a contracted panicle, much laterally compressed, one-fid; empty glumes two, scarcely exceeding the flowering ones, rigid, long, narrow, keeled; flowering glumes rigid, slightly pedicelled, with an oblique callus, and a small pencil of silky hairs at the base. P. arenaria is, on some parts of the coast, employed for binding sea sandbanks; it is also used for making mats and thatch. It grows freely in any sandy soil, and may be raised from seeds, but is most readily increased by cutting the long, creeping rhizomes into pieces, and planting them where required.
P. arenaria (sand-loving). fl., spikelets erect; pedicels scabrid; panicle white, sub-cylindric, 3in. to 6in. long, straight, broadest and sometimes lobed at base, the branches short. July. l. long, rigid, convolute, polished without, scabrous and glaucous within; sheaths long; ligule very long, bifld. Stems 2ft. to 4ft. high. Rootstock widely creeping. (Sy. En. B. 1722.) P. baltica (Baltic). This is very similar to P. arenaria; it chiefly differs in its looser, less cylindric panicles. (J. B., 1872, 127.)