British NVC community OV21

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.

There are three subcommunities:

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

Rodwell, John S, ed. (March 2000). Maritime communities and vegetation of open habitats. British Plant Communities. Vol. 5. Cambridge University Press. ISBN 978-0-521-39167-2.