It is native to Europe, but in the cooler areas of North America was widely used as a pasture grass until the 1940s. Although it has largely been replaced by soybeans and more palatable grasses, it still gets some use in poor soils. It was one of the grasses planted in areas disturbed by the Trans-Alaska Pipeline. It generally does well in response to fires, due to survival of rhizomes and seeds.
It can be found in open woodland, rough grassland, hedgerows, roadsides and waste ground, and as a weed on arable land.
This species is similar to Agrostis stolonifera, with the key difference being that the latter has stolons. In fact the two are sometimes treated as a single species, and it is not always clear precisely what an author means by Agrostis alba or Agrostis stolonifera.
Many internet sources describe Agrostis capillaris as being the tallest of the bent species. However C E Hubbard describes its height as ranging from 10 to 70 cm high, whereas Agrostis gigantea is 40–120 centimetres (16–47 in). Marjorie Blamey, Richard and Alastair Fitter also describe black bent as being taller.
The leaves are dull green. The ligule is blunt, but toothed and up to 6 millimetres (0.24 in) long.
The panicle is open and loose, of green or purplish colour. It flowers from June to August.
The leaves are rolled in shoot, not hairy, no auricles, but the plant has rhizomes.
- John Hilty (November 23, 2007). "Redtop". Grasses, Sedges, and Non-Flowering Plants of Illinois. Archived from the original on December 12, 2007. Retrieved December 17, 2007.
- BSBI List 2007 (xls). Botanical Society of Britain and Ireland. Archived from the original (xls) on 2015-06-26. Retrieved 2014-10-17.
- "Agrostis gigantea". Fire Effects Information System. United States Forest Service.
- C E Hubbard (1978). Grasses. Penguin Books.
- Marjorie Blamey, Richard and Alistair Fitter (2003). Wild Flowers of Britain and Ireland. ISBN 0-7136-5944-0.
- "Agrostis gigantea Roth". Wisconsin Botanical Information System. Archived from the original on September 14, 2006. Retrieved December 13, 2007.
- "Red top". Ada Hayden Herbarium. Archived from the original on 2007-12-28. Retrieved December 13, 2007.
- Clayton, W.D.; Vorontsova, M.S.; Harman, K.T.; Williamson, H. "Agrostis gigantea". GrassBase - The Online World Grass Flora. Royal Botanic Gardens, Kew.
- "Black Bent". Skye Flora. Archived from the original on November 11, 2007. Retrieved December 13, 2007.
- "Agrostis gigantea Roth". Grassland Species Profiles. Archived from the original on November 11, 2007. Retrieved December 13, 2007.