British NVC community OV21 (Poa annua - Plantago major 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 ubiquitous in the lowlands and upland fringes of Britain wherever there is suitable habitat.

There are three subcommunities.

Community composition

The following constant species are found in this community:

• Scented mayweed (Matricaria chamomilla)
• Greater plantain (Plantago major)
• 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 community is ubiquitous in the lowlands and upland fringes of Britain. In rural areas it is found wherever farm tracks and gateways are heavily trampled; in urban areas it is a feature of recreational areas and wasteland, and can replace the Poa annua - Sagina procumbens community, OV18

British NVC community OV18

British NVC community OV18 is one of the open habitat communities in the British National Vegetation Classification system...

, in paved areas where crevices are large enough to permit the establishment of more robust vascular plants.

Subcommunities

There are three subcommunities:

• the so-called typical subcommunity
• the Lolium perenne subcommunity
• the Polyonum aviculare - Ranunculus repens subcommunity