THE BRYOPHYTES OF CORNWALL
AND THE ISLES OF SCILLY

*1: Tresco, 1967, JAP (BBSUK) (Paton 1974b, 1975: 11).

*2: Unshaded on near-horizontal, gravelly, china-clay spoil of sparsely vegetated bank above quarry, Melbur, NW. of St Austell, SW95, 1998, DTH 98-64 (BBSUK, DTH) (Blackstock 1999: 38).

First recorded in Isles of Scilly (in and nearAbbey Gardens on Tresco) in 1962 (Paton 1974b, 1999: 392), and present on all five inhabited islands by 1996. A more recent colonist of Cornish mainland, where first recorded in 1997, when it was found to be plentiful over many metres of abandoned trackway near old china clay works at Cold Harbour (vc1). In March 1998 substantial patches were discovered in vc2 over small areas in the St Austell china-clay district at Melbur and Twin Peaks, but soon afterwards it was found to be locally dominant and much the commonest bryophyte over >10 ha of china clay spoil at Stannon on the western slopes of Bodmin Moor. Small patches were found elsewhere in the St Austell china-clay district in 1999, at Melbur and around High Street, Foxhole. Besides the find at Stannon, several substantial to large patches have now been found at other outlying china-clay pits (1999, SE. of Hawk's Tor; 1999, several places NNE. of St Neot).

Since 1998 also recorded in vc2 at a few localities away from china-clay workings: at Milltown (SX 114681: 1999, one patch at edge of track surfaced with china-clay spoil); edge of track surfaced with china-clay spoil SE. of Trewarmett (2000); in granite quarries (2001, at De Lank and Hantergantick Quarries); on unshaded edge of cliff-top footpath near Bossiney (JAP pers. comm., 2000); near Lockengate (SX0361, on track, 2005).

Colonises bare acidic substrates, forming dense low patches that may become a metre or more across. Widespread on Isles of Scilly by 2003, occurring on variety of humic, acid, often peaty or rocky soils, mainly in open or lightly shaded places, on cliffs, coastal heaths, roadsides, in scrub and in groves of trees. Less common in Scilly than Lophocolea semiteres, and preferring somewhat damper sites, although they sometimes occur together.

On mainland, mostly grows on clayey, gritty and gravelly china-clay spoil of banks above working quarries, spoil heaps, about works and depots, and disused tracks and track edges, locally on mica dam edges. Initially colonises mostly sparsely vegetated, unshaded surfaces, but persists at base of grasses and herbs as cover of phanerogams begins to develop, although lost when ground fully shaded with litter layer developing. Less typical habitats: Twin Peaks, vc2: on damp, compressed, sandy soil near unshaded edge of tarmac of road, near china clay quarry. Stannon: bit on china clay spoil in hollows subject to frequent inundation. Near Greensplat in small amount with other bryophytes on old concrete. Rosevear: patch on thin soil on top of mortared-stone wall.

Often in pure patches, but at Stannon and elsewhere also associated with virtually all of the bryophytes and small phanerogams of open acid soils, especially Ceratodon purpureus, Nardia scalaris, Pogonatum urnigerum, but also Archidium alternifolium, Atrichum undulatum, Blasia pusilla, Campylopus pyriformis, Cephalozia bicuspidata, Gymnocolea inflata, Solenostoma gracillimum, Lophocolea bidentata, Lophozia incisa Pohlia annotina, Polytrichum piliferum, Rhytidiadelphus squarrosus, Scapania compacta, Scapania irrigua, Pseudoscleropodium purum, low grasses (e.g. Holcus lanatus), low herbs (e.g. Sedum anglicum) and young plants of taller phanerogams (e.g. Agrostis sp., Calluna vulgaris, Erica cinerea, Vaccinium myrtillus).

Both sexes occur in Isles of Scilly, where sporophytes are reported (maturing 3-5, 8: Paton 1999: 392). All material checked from mainland of Cornwall has proved to be female only (from St Austell area in tetrads: SW95C, 95D, 95H, 95R, 95S, 95U, 95W, 95X, SX05C, 05H, 05I) as were the Hawk's Tor and St Neot plants (SX 17M, 17V).

Lophocolea bispinosa was presumably introduced to the Isles of Scilly with horticultural plants from the Southern Hemisphere. Its later spread on the mainland may involve a single clone of female plants. The plants are very brittle and they also produce filiform branches, so dispersal by vehicles in the china-clay districts seems likely, especially as many records are alongside tracks. At least three outlying localities in vc2 are at sites where china-clay spoil has been used to surface tracks.

Recorded on mainland cper: 2, 3, 5; female bracts formed but perianths not yet developed 9, 12.