Ontario Weeds: Silky bent grass

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Excerpt from Publication 505, Ontario Weeds, Order this publication

Table of Contents

  1. Name
  2. Other Names
  3. Family
  4. General Description
  5. Stems and Roots
  6. Flowers and Fruit
  7. Habitat
  8. Similar Species
  9. For more information...

Name: Silky bent grass, Agrostis spica-venti.,

Other Names: APESV, agrostide, jouet-du-vent, Loose silky bent grass, Wind grass, Apera spica-venti (L). Beauv.

Family: Grass Family (Gramineae)

General Description: Winter annual or annual, reproducing only be seed.

Photos and Pictures

Silky bent grass. A. infestation in winter wheat B. shattered seed on soil surface under A

Silky bent grass. A. infestation in winter wheat
B. shattered seed on soil surface under A

Stem and leaf-base characteristics of a typical grass.
Stem and leaf-base characteristics of a typical grass.

Stems & Roots: Stems erect to a height or 150 cm (60 in.) unbranched, sheaths smooth with separate, membranous margins; ligule membranous 2-14mm (1/12 - 1/2 in.), short and pointed in very young plants but lengthening with age, becoming rather firm and the tip somewhat torn or toothed, its margins continuous with the membranous margins of the sheath; no auricles; leaf blades long (up to 30cm, 12in.), flat, 0.5-6mm (1/50 - 1/4 in.) wide, gradually tapering towards the tip; stem nodes distinctly darker than the stem or leaf sheaths.

Flowers & Fruit: Panicle at first narrow and dense, becoming open and loosely branched, up to 35cm (14in.) long and 25cm (10in.) wide, with numerous fine branches each ending in a single spikelet 1.5 - 3.2 (1/16 - 1/8 in.) long; the while inflorescence conspicuously reddish at maturity; each spikelet containing a single floret ("seed") with a slender awn 4-9mm (1/6 - 3/8 in.) long; seed without its awn is about 1.6mm (1/15in.)long. Flowers from June to August.

Habitat: Originally introduced from Europe. Silky bent grass is a common weed in fields of winter wheat and fall rye on sandy soils in the "tobacco belt" of southwestern Ontario. It also occurs in ditches and other non-cultivated areas.

Similar Species: It is distinguished from other common annual grasses by its winter annual habit, its slender stems and leaves with long, 1-several-pointed, membranous ligules, its loose, open,reddish, mature inflorescence and the short, straight awn on each seed.

Related Links

... on general Weed topics
... on weed identification, order OMAFRA Publication 505: Ontario Weeds
... on weed control, order OMAFRA Publication 75: Guide To Weed Control


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For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca
Author: OMAFRA Staff
Creation Date: 01 June 2000
Last Reviewed: 01 November 2003