M22
Juncus subnodulosus fen-meadow is a widespread but uncommon community throughout lowland England and Wales. It is essentially a type of damp pasture that occurs where base-rich groundwater springs or surface water streams arise from chalk or limestone soils. It is often a species-rich type of vegetation with a mixture of grasses and rushes and a wide selection of
forbs. The most characteristic plants are rushes, most commonly
blunt-flowered rush but sometimes
hard rush and
jointed rush in varying proportions or even replacing it altogether towards the edge of its range.
Soft-rush and
sharp-flowered rush are much less likely, as they indicate more acidic conditions. The rushes are normally mixed with some sedges such as
lesser pond-sedge,
brown sedge and
glaucous sedge. Amongst the rushes and sedges there are always several species of grass and usually many other flowering plants, but the abundance of these is likely to be heavily influenced by the level of grazing. The most common grasses are
common reed and
Yorkshire-fog, with
purple moor-grass sometimes present in the more acid stands and
quaking-grass in alkaline conditions.
Marsh-thistle,
meadowsweet and
water-mint are the commonest herbs to be found. M22 may contain a large number of rare or scarce plants. These include
milk-parsley (in East Anglia),
meadow-rue,
marsh lousewort,
long-stalked yellow-sedge and
marsh valerian. There are four subcommunities of M22: • M22a typical subcommunity conforms to the general community description • M22b
Briza media-
Trifolium spp. is a slightly more calcareous and species-rich variant with less dominance by rushes and more flowering herbs such as
southern marsh-orchid,
early marsh-orchid and
marsh helleborine • M22c
Carex elata vegetation is found on more peaty substrates, including old raised mires, and may contain
Thelypteris palustris • M22d
Iris pseudacorus subcommunity is characterised by the dominance of taller plants such as
common reed,
meadowsweet and
meadow-rue. ==Conservation==