Triplasis purpurea, the purple sand-grass, is a species of grass in the family Poaceae native to North America.

Its wiry, tufted culms are either widely spreading or ascending, with pubescent nodes.

The leaf sheathes and small, rigid leaves of the grass are scabrous.

The rose-purple spikelets of the grass are 5–8 mm (0.20–0.31 in) long with two to five flowers and have rather short pedicels.

[1] Triplasis purpurea is endemic to North America, mostly throughout along eastern coast but also in the midwest.