British NVC community OV4 (Chrysanthemum segetum - Spergula arvensis community) is one of the open habitat

Vegetation of open habitats in the British National Vegetation Classification system

This article gives an overview of the plant communities formed by vegetation of open habitats in the British National Vegetation Classification system.-Introduction:...

 communities in the British National Vegetation Classification

British National Vegetation Classification

The British National Vegetation Classification or NVC is a system of classifying natural habitat types in Great Britain according to the vegetation they contain....

 system. It is one of six arable weed and track-side communities of light, less-fertile acid soils.

It is a widely-distributed community. There are two subcommunities.

Community composition

The following constant species are found in this community:

• Corn marigold (Chrysanthemum segetum)
• Annual meadow-grass (Poa annua
  Poa annua
  Poa annua, or annual meadow grass , is a widespread low-growing turfgrass in temperate climates. Though P. annua is commonly considered a solely annual plant due to its name, perennial bio-types do exist. 'Poa' is Greek for fodder. It is one of the sweetest grasses for green fodder, but less ...
  
  )
• Knotgrass (Polygonum aviculare
  Polygonum aviculare
  Polygonum aviculare or Common Knotgrass is a plant related to buckwheat and dock. It is also called birdweed, pigweed and lowgrass. It is an annual found in fields and wasteland, with white flowers from June to October....
  
  )
• Corn spurrey (Spergula arvensis)

No rare species are associated with the community.

Subcommunities

There are two subcommunities:

• the so-called typical subcommunity
• the Ranunculus repens - Sonchus asper subcommunity