Character:  Couch forms into large tufts, with the rhizomes spreading underground

 

Flower:  The spikes vary in length, and alternate in two rows lying close to the stem.  The distance between each spikelet varies.  The appearance of the spikelet also varies, sometimes they are spread out along the stem, or they can be tightly packed. An identifying feature between Couch
and Rye-grass is that Couch spikelets lie with their flat side to the stem, while Rye-grass spikelets have their rounded side to the stem.  Seed production is generally low compared to other grasses, and seeds are only viable if the flowers have been pollinated. One flowering head can produce up to 20 viable seeds that will germinate in the autumn if they are in the top 70mm of soil.  Seeds can survive for 4 to 5 years.

 

Significance:   This pernicious weed spreads rapidly through arable land, causing significant yield losses in all the major crops. The rhizomes spread through the soil developing new plants wherever a node occurs.  Growth is rapid when the crop is open and soil conditions are ideal.  Couch can be spread through cultivations, which chop-up the rhizomes. If a piece has a node it will grow as an independent plant.