Cynodon dactylon, also known as Vilfa stellata dūrvā grass, Dhoob, Bermuda grass, dubo, dog's tooth grass, Bahama grass, devil's grass, couch grass, Indian doab, arugampul, grama, wiregrass and scutch grass, is a grass that originated in the Middle East.Although it is not native to Bermuda, it is an abundant invasive species there. It is presumed to have arrived in North America from Bermuda, resulting in its common name. In Bermuda it has been known as crab grass.The blades are a grey-green color and are short, usually 2–15 cm (0.79–5.91 in) long with rough edges. The erect stems can grow 1–30 cm (0.39–11.81 in) tall. The stems are slightly flattened, often tinged purple in colour.The seed heads are produced in a cluster of two to six spikes together at the top of the stem, each spike 2–5 cm (0.79–1.97 in) long.It has a deep root system; in drought situations with penetrable soil, the root system can grow to over 2 metres (6.6 ft) deep, though most of the root mass is less than 60 centimetres (24 in) under the surface. The grass creeps along the ground and roots wherever a node touches the ground, forming a dense mat. C. dactylon reproduces through seeds, runners, and rhizomes. Growth begins at temperatures above 15 °C (59 °F) with optimum growth between 24 and 37 °C (75 and 99 °F); in winter, the grass becomes dormant and turns brown. Growth is promoted by full sun and retarded by full shade, e.g., close to tree trunks.