THE BRYOPHYTES OF CORNWALL
AND THE ISLES OF SCILLY

*1: Lamorna, 1882, WC (NMW) (Paton 1969a: 692).

*2: St Minver, 1906, RWS (TRU) (Paton 1969a: 692).

Recent molecular studies show that this taxon comprises a complex of cryptic species in Britain, with few morphological differences (D. G. Long pers. comm.).

Very large Aneura with thalli up to 10 mm wide from a shaded, flushed streambank near Lesnewth (DTH) raised hopes that A. maxima (Schiffn.) Steph. was at hand, but detailed study by JAP reidentified it as a large form of A. pinguis. Similarly large plants have also been seen on flushed ground with Chrysosplenium oppositifolium inside a Grey Willow carr near Trekeivesteps. Very large plants with long wide thalli were found a number of times in flushes in woodland (e.g. DTH 07-477), but although as large as A. maxima they do not show its other characters.

The wide range of habitat types occupied by this taxon may reflect occurrence of more than one morphologically cryptic species (see above). In Cornwall it occurs in at least three contrasting habitat types: (a) strongly acidic, peaty and unshaded; (b) mildly acidic, on mineral soils, often well shaded; (c) basic and unshaded.

Detailed habitat notes from Cornwall are as follows. On damp peaty or humic partly bare surfaces on heaths, on sphagna, mineral soils and damp humic litter in mires, stream edges and flushes above sea-cliffs (with Calliergonella cuspidata, Calypogeia fissa, Straminergon stramineum, Cephalozia bicuspidata, Kurzia pauciflora, Pellia endiviifolia, Riccardia chamedryfolia, Riccardia multifida, Sphagnum capillifolium, Sphagnum denticulatum; Anagallis tenella, Drosera rotundifolia, Narthecium ossifragum). On damp soil of partly bare patches along old tracks in heathland; bit in damp hollow on track in old mining ground, part shaded. Unusual record of small patches on open soil of heap amongst mine-spoil. Colonist on damp clay e.g. of flushed areas, of china clay quarry slopes, banks above working quarries and on spoil heaps, track edges, almost unshaded or partly shaded (with Anthoceros punctatus, Pellia neesiana, Philonotis fontana). Damp sand at edges of mica dams. On wet peaty humus of flush on slope above N.-facing sea-cliff, unshaded. With low mosses on unshaded, calcareous sandy substrate of flush on slope above sea-cliff (with Cratoneuron filicinum, Didymodon tophaceus). On open, flushed, calcareous sand of floor of sandpit in dunes (with Bryum pseudotriquetrum, Calliergonella cuspidata, Cratoneuron filicinum, Drepanocladus aduncus, Pellia endiviifolia, Petalophyllum ralfsii). Frequent in flushes and edges of small streams in deciduous woodland and Grey Willow carrs, growing on old fern bases, fern and other plant litter and intermixed with mosses, or on thin soil over wet rock, once on stream bank (associates include Calliergonella cuspidata, Chiloscyphus polyanthos s. l., Oxyrrhynchium speciosum, Pellia neesiana, Rhizomnium punctatum, Chrysosplenium oppositifolium). Beneath Grey Willows at upper edge of inundation-zone beside reservoir. On soil of gentle slope in open grove of deciduous trees. On wet clay near base of walls of ruin of china-clay dry, shaded by trees (very large plants). Small patch on partly bare soil on unshaded slope in old mine area, beside road. On wet ground amongst mine-spoil, at base of Juncus effusus. Damp soil of old metalliferous mine under edge of scrub (with Riccardia chamedryfolia). At normal water level on wet slaty rock in R. Camel with Hygroamblystegium fluviatile, partly shaded by trees and frequently inundated.

Commonly c.fr.: immature 1-3, 5, 12.