British NVC community OV19 (Poa annua - Matricaria perforata 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 communities characteristic of gateways, tracksides and courtyards.

This community is found throughout the lowlands of Britain wherever there is suitable habitat.

There are five subcommunities.

Community composition

The following constant species are found in this community:

• Shepherd's-purse (Elymus repens)
• Scentless mayweed (Matricaria perforata
  Matricaria perforata
  Tripleurospermum inodorum is the type species of Tripleurospermum.Historically included the genus Matricaria, Tripleurospermum inodorum has been the subject of some controversy, with many revisions in recent years. The Flora Europaea uses Matricaria perforata for this species...
  
  )
• 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 ...
  
  )

There are no rare species associated with the community.

Distribution

This ephemeral community is widely distributed throughout the lowlands of Britain. Characteristic habitats are on farm tracks, around gateways where trampling is only moderate, and on verges alongside roads, wherever disturbance and spray-wash from vehicles prevents the development of a closed perennial sward.

Subcommunities

There are five subcommunities:

• the Senecio squalidus - Epilobium angustifolium subcommunity
• the Lolium perenne - Capsella bursa-pastoris subcommunity
• the Atriplex prostrata - Chenopodium album subcommunity
• the Chamomilla suavolens - Plantago major subcommunity
• the Elymus repens subcommunity