British NVC community OV1 (Viola arvensis - Aphanes microcarpa 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 no subcommunities.

Community composition

The following constant species are found in this community:

• Slender parsley-piert (Aphanes australis)
• 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 ...
  
  )
• Sheep's sorrel (Rumex acetosella
  Rumex acetosella
  Rumex acetosella is a species of sorrel, also known as Acetosella vulgaris Fourr, bearing the common names sheep's sorrel, red sorrel, sour weed, and field sorrel. The plant and its subspecies are common perennial weeds. It has green arrowhead-shaped leaves and red-tinted deeply ridged stems, and...
  
  )
• Field pansy (Viola arvensis
  Viola arvensis
  Viola arvensis is a species of violet known by the common name field pansy. It is native to Europe, western Asia, and North Africa, and it is known on other continents as an introduced species and a weed of disturbed and cultivated areas....
  
  )

Two rare species are associated with the community:

• Annual vernal-grass (Anthoxanthum aristatum
  Anthoxanthum aristatum
  Anthoxanthum aristatum is a species of grass known by the common name annual vernalgrass. It is native to North Africa and southern Europe as far north as France, and it is known in other regions, including northern Europe and North America, as an introduced species. It is occasionally a minor weed...
  
  )
• Lesser quaking-grass (Briza minor
  Briza minor
  Briza minor is a species of grass known by the common namesLesser quaking-grass or little quakinggrass. It is native to the Mediterranean Basin, and it is known elsewhere, including much of North America, as an introduced species. It is an annual grass producing narrow clumps of erect stems up to...
  
  )

Distribution

This community is typically associated with arable crops on impoverished soils and is now very scarce, both because suitable soils have a localised distribution and because intensive cereal agriculture is not conducive to its development. It is found very locally, mostly in southern and eastern Britain, most often in fields of barley

Barley

Barley is a major cereal grain, a member of the grass family. It serves as a major animal fodder, as a base malt for beer and certain distilled beverages, and as a component of various health foods...

 or fallow arable.