*1: Mean Rock, N. of
Constantine, 1838, EAW (TRU) (Paton 1969a: 711).
*2: Roche, 1879, RVT
(B) (Paton 1969a: 711).
Habitat notes from C&S are as follows.
Commonest on well drained, acidic soil (stony, sandy, gravelly
or humic), such as in barer patches on heathland or acid
grassland, on tops or sides of 'hedges', on old copper
mine-spoil, about old quarries and their spoil heaps (granite,
china clay, serpentinite, slate), on disused tracks or track
edges, thin soil overlying rocks, on wall tops and on graves.
Unlike Polytrichastrum
formosum, it usually appears intolerant of more than light
shading, although recorded on slopes in open deciduous
woodlands, on tracks in conifer plantations, in clearings or
on banks at woodland edges, and a few times in small quantity
on banks under mature deciduous trees. Although a colonist of
bare substrates such as those in and around quarries and their
spoil heaps, it generally requires surfaces that have been
stable for several years, and is later lost as taller
phanerogams invade. Frequent on cliff tops (serpentinite,
granite, slates) and coastal slopes, sometimes in very exposed
situations on headlands, so evidently tolerant of salt-spray.
One record of small patches in upper part of inundation-zone
of a reservoir. Absent from calcareous dunes, but in Isles of
Scilly often on acidic dune sand. Two records of small amounts
in sites that appeared base-rich (thin soil on old mortared
wall, thin soil over exposed serpentinite) were presumably on
leached substrates. Less typical sites include colonising old
tarmac on bridge on minor road and on a disused track, a
cemetery path and the edge of a lane, as weed on soil of plant
pots in nursery, on soil in garden, colonising edge of short
grassland of old lawn, on gravel beside sewage farm and on
track of disused railway. Recorded associates include Cephaloziella
divaricata, Hypnum
cupressiforme var.
lacunosum, Pogonatum urnigerum,
Polytrichum
piliferum, Scleropodium touretii,
Conocephalum
conicum, many low herbs e.g. Aphanes, low Calluna vulgaris. Less
often e.g. Tortula
viridifolia.
A form with a short hyaline tip to leaf point was
found twice in coastal sites (SW. of Lamorna Cove; on St
Martin's).
Frequently or commonly c.fr.: capsules immature
1-6, 8-12; dehiscing 6-9; dehisced [1-4: old],
8-11.
