Cynosurus cristatus, the crested dog's-tail, is a short-lived perennial grass in the family Poaceae, characterised by a seed head that is flat on one side.

[citation needed] It is perennial with a slighted tufted habit, a slender stem, 15 to 45 cm high, leafy at the base and thus suitable for grazing by sheep.

The lower side of the leaf is smooth, glossy and keeled.

Other grasses with glossy leaves include Lolium perenne and Poa trivialis.

It is found in most parts of Europe and South West Asia, and has been introduced into North America, Australia and New Zealand, from near sea level up to about 2000 feet, in all soil types.