Agrostis gigantea Roth - Redtop, Black Bent or Red Top Bent.

Taxonomic position.

Family Poaceae, genus Agrostis.


Agrostis alba L. subsp. gigantean (Roth) Jir., A. diffusa Host, A. graniticola Klok., A. praticola Klok., A. stolonifera L. subsp. gigantean (Roth) Beldie, A. stolonifera subsp. gigantea (Roth) Maire & Weiller, Cinna karataviensis Pavl., Agrostis alba auct.

Biological group.

Perennial rhizome weed.

Morphology and biology.

Stem upright or ascending, 30-120 cm in height. Leaves linear-lanceolate, usually flat, 2-8 mm in width, rough. Ligule 2-6 mm in length, split at apex. Panicle 7-20 cm in length, loose, after flowering compressed, with upward directed branchlets. Spikelets brownish-violet or greenish. Spikelet scales pointed, rough along keel. The lower floral scale (palea) without rachis or rarely with very short, easily dropping rachis; the lower palea much shorter than lower one. Anthers 1-1.5 mm in length. The plant is green. Blossoms in June-July, fructifies in July-August.


The European part of the former USSR; the Caucasus, Western and Eastern Siberia; the Far East (introduced); Central Asia. General distribution: Scandinavia, Atlantic and Middle Europe, the Mediterranean, Asia Minor, Iran, the Himalayas, Mongolia.


The species inhabits meadows, riverside sands, pebbles, forest edges, sparse forests, bushes along roads, humid meadows and fallow lands, meadow bogs, banks of water reservoirs, seaside salted meadows, fields and plantations of agricultural crops, upper belt of mountains, occurring everywhere on damp, grassy places.

Economic significance.

The plant occurs occasionally as a weed in crops of winter grains, most often rye, in kitchen gardens and orchards, in crops of perennial grasses, and in settlements as a ruderal plant. It is found in forest zones mainly, losing its significance as a weed plant southward and not found among crops. The main control measures include use of a correct system of soil treatment with multiple-field crop rotation, use of bare and occupied fallows and cleaning of seed material.

Reference citations:

Gubanov I.A., Kiseleva K.V., Novikov V.S., Tikhomirov V.N. 2002. The illustrated keys to plants of Middle Russia. V. 1, Moscow: KMK, 526 p. (in Russian).
Minyaev N.A., ed. 1970. Synopsis of flora of Pskov Region. Leningrad: Leningrad University. 176 p. (in Russian).
Nikitin V.V. 1983. Weeds in the flora of the USSR. Leningrad: Nauka. 454 p. (in Russian).
Tsvelev N.N. 1976. Cereals of the USSR. Leningrad: Nauka, 788 p. (in Russian).

© Luneva N.N.

N.N.Luneva is the author of image.

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