British NVC community OV21

British NVC community OV21 (Poa annua - Plantago major community) is one of the open habitat communities in the British National Vegetation Classification 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)

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, 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