*1: Trungle Moor near Paul, 1866, WC (PNZ) (Paton 1969a: 740).
*2: Probus, 1861, ES (TRU) (Paton 1969a: 740).
See account of P. caespitosa for notes on occurrence of plants intermediate between P. fontana and that species.
Grows as tufts or patches that may be extensive and pure, forming low lawns. Notes on habitats in Cornwall are as follows. Characteristically in damp or wet places (often at edge of shallow trickling water) with slight to moderate base enrichment, on soil (often humic, peaty, or clayey, or among gravel) or in thin soil accumulations on rock (granitic, slaty, horizontal to vertical; occasionally on concrete or old crumbling tarmac). Most sites are open or only lightly shaded, less often in moderate shade (once in rather heavy shade in deciduous woodland). Habitat types in which it occurs are most commonly flushes (often apparently acidic, on moorland, wet heathland, cliff-slopes or in poor pastures, less often in open deciduous woodland), gravelly or rocky tracks (e.g. across heaths or moorland), roadside verges, ditches, beside streams, in old mine areas, granite quarries and their spoil, clay-pits, around old china-clay 'dries' and on newer concrete in china-clay works, damp china-clay spoil, with single records from a disused railway cutting, a woodland clearing, moist peat of heathland on the Lizard, on a rock emergent from a stream and tarmac of a sheltered lane. An unusual record was of a patch in a wheat stubble field (CDP). Associates recorded include Aneura pinguis, Archidium alternifolium, Brachythecium rivulare, Bryum alpinum, Bryum pallens, Bryum pseudotriquetrum, Calliergonella cuspidata, Chiloscyphus pallescens, Trichodon cylindricus, Fossombronia incurva, Pellia neesiana, Pohlia annotina, Pohlia melanodon, Pohlia wahlenbergii var. wahlenbergii, Platyhypnidium riparioides, Riccardia chamedryfolia, Riccia sorocarpa; Equisetum palustre, Eriophorum angustifolium, Juncus effusus, Molinia caerulea.
One record cfr, capsules immature 6.