Triglochin palustris or marsh arrowgrass is a species of flowering plant in the arrowgrass family Juncaginaceae. It is found in damp grassland usually on calcareous soils, fens and meadows. The species epithet palustris is Latin for "of the marsh" and indicates its common habitat. It has a circumboreal distribution, occurring throughout northern parts of the Northern Hemisphere. It can be found locally in the British Isles especially the north. (Wikipedia)