Synonymy

Sphagnetum Rankin 1911b p.p.; Sphagnum hummock complex, Sphagnum papillosum & S. rubellum phases Rose 1953; General bog communities Newbould 1960 p.p.; Valley bog Ward et al. 1972ap.p.; Sphagnum lawn bog hummocks NCC New Forest Bogs Report 1984.

Constant species Calluna vulgaris, Drosera rotundifolia, Erica tetralix, Eriophorum angustifolium, Molinia caerulea, Narthecium ossifragum, Sphagnum papillosum.

Rare species

Agrostis curtisii, Erica ciliaris, Hammarbya paludosa.

Physiognomy

The Narthecio-Sphagnetum comprises mire vegetation dominated by carpets of Sphagna with scattered herbs and sub-shrubs, forming extensive lawns or the drier areas within low-amplitude hummock/hollow systems. The dominant Sphagnum is generally S. papillosum, the cover of which can be very extensive and luxuriant, but there is quite frequently some S', auriculatum or S.recurvum (very occasionally both) and sometimes S. cuspidatum occurs too, all these species tending to increase in prominence in wetter areas, where they may mark a transition to Rhynchosporion pool vegetation. Much more locally, the community provides important stations for S. magellanicum and S. pulchrum, both scarce species in south-eastern Britain, but sometimes growing in abundance here: the former is plentiful on some New Forest bogs (as on Cranesmoor: Newbould 1960, NCC New Forest Bogs Report 1984), the latter especially striking in some stands around Poole Harbour in Dorset (Ratcliffe 1977). Then, there are occasional records for S. subnitens and S. tenellum, with S. capillifolium occurring infrequently and usually on the tops of drier hummocks. In contrast to the Ericetum tetralicis, to which this vegetation often grades on drier ground, S. compactum is hardly ever found.

Other mosses are few in number and generally of low cover (Hypnum jutlandicum and Aulacomnium palustre are sometimes present) but the moist Sphagnum carpet provides a very congenial surface for a variety of hepatics, with patches of leafy liverworts often adding to the mosaic of colour over the ground. Odontoschisma sphagni and Kurzia pauciflora are the commonest species overall, but Cladopodiellafluitans, Cephalozia macrostachya, C. connivens, C. bicuspidata and Calypogeia fissa have also been recorded. In contrast to the stands described by Rose (1953), however, Mylia anomala has not been found very frequently. There can also be scattered thalli of Aneura pinguis and various Riccardia ssp. including R. chamedryfolia. Lichens are typically sparse, though the decaying tops of taller hummocks can provide a habitat for Cladonia impexa, C. arbuscula and C. uncialis.