carpet grass

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of several coarse, sod-forming grasses of the chiefly New World genus Axonopus, especially A. affinis, cultivated for turf and pasture in warm humid regions.

Wiktionary

1. n. Any of the genus Axonopus of American tropical and subtropical grasses, some of which are rhizomatous.

WordNet 3.0

1. n. grass native to West Indies but common in southern United States having tufted wiry stems often infested with a dark fungus