*1: Near Hayle, 1867,
WC (PNZ) (Paton 1969a: 727).
*2: St Minver, 1891,
RVT (B) (Paton 1969a: 727). [Earlier report
(Seaton, FB, in Holmes & Brent 1869) not supported by
specimen: Paton 1969a: 727].
Easily confused with non-fertile Barbula unguiculata,
especially forms of that species with small, strongly
papillose leaf cells and leaf margins less recurved than
usual. Recognition of named varieties of T. brachydontium has
been abandoned in Britain
(Corley & Hill 1981: 84, cf. Warburg 1963: 45; Smith 1978:
291) because intermediates are common, but in Cornwall
the form typical of shaded inland banks is considerably larger
than that usual on coastal cliffs (as e.g. in Mnium
hornum).
Grows as usually pure patches or low lawns. Habitat
notes from C&S are as follows. Often very common in
coastal sites, in wide range of mainly unshaded or lightly
shaded, fairly dry habitats with patchy or low vegetation,
including soil on cliff-tops and slopes, low creekside cliffs,
on 'hedges' and banks on and above sea-cliffs, crevices in
walls, soil on wall tops, rocks and soil beside streams, and
in short dune grassland. Grows on wide range of substrates on
coasts, from calcareous sand and loamy soil to thin soil
layers over rock or in earthy crevices (of slaty, granitic,
gabbro or serpentinite rocks, also old concrete and mortar)
and on spoil from metalliferous mines. A few records from
coastal sites were on wet substrates or in rather heavy shade,
e.g. in cliff-top crevices, flushed rock in sea-cave, under
trees, or a stream bank inside Grey Willow
carr.
Less common inland in Cornwall than on the coasts,
but large patches occur well inland in old slate and granite
quarries, on roadside or laneside banks, on 'hedges', graves,
old walls, over old concrete, on masonry debris in woodland,
and occasionally on open metalliferous mine-spoil. Unlike its
coastal sites, those inland are most often partly to well
shaded (usually by deciduous trees) and often in very humid
places (e.g. near streams and in rock cuttings and on large
damp old mortared wall), but at least a few inland records are
from open exposed sites. Inland records commoner than
elsewhere on the Lizard pen. on serpentinite bedrock and
overlying soils. There, however, it occurs not only under
trees and inside woodland (e.g. streambank in Bonython
Plantation), but often also in the open (e.g. on soil on a
track, and in rather bare places on peaty soil of open
heathland) and partly shaded (e.g. on
banks).
Associates recorded at coastal sites include Aloina aloides, Archidium
alternifolium, Bryum dichotomum, Bryum donianum, Bryum dichotomum, Campylopus
introflexus, Cephaloziella sp., Ceratodon purpureus,
Didymodon fallax,
Didymodon luridus,
Fissidens
adianthoides, Fossombronia
'husnotii', Pleuridium acuminatum,
Pleurochaete
squarrosa, Saccogyna viticulosa,
Scleropodium
touretii, Tortella
flavovirens, Conocephalum conicum,
Sedum anglicum;
less often Bryum
kunzei, Bryum
torquescens, Cephaloziella
stellulifera, Gongylanthus
ericetorum, Grimmia
lisae, Lophozia
excisa, Polytrichum
juniperinum, Riccia
subbifurca, Scleropodium touretii,
Tortula
viridifolia, Tortula wilsonii, Weissia longifolia
var.
longifolia; also varied low herbs, e.g. Aphanes sp., and
grasses. Noted inland with Aloina aloides, Dicranella varia, Didymodon insulanus,
Fossombronia
caespitiformis, Lejeunea lamacerina,
Rhynchostegium
confertum, Saccogyna viticulosa,
Conocephalum
conicum.
Rarely c.fr. (five records, mostly of few
capsules): capsules immature 1, 9; dehisced 9.