*1: Bark of horizontal
part of dead trunk of Pinus radiata tree, ca 1.5 m above ground;
partly shaded, in open area of plantation; Abbey Hill, Tresco,
SV8911, 1995, DTH 95-324 (BBSUK, DTH, E)
(Holyoak 1996, Blockeel 1997: 46).
*2: On rotting stump, Par
churchyard, St Blazey Gate, SX0553, 2004, JAP 2871
(BBSUK) (Rothero 2005:
42).
Discovered new to Britain in the Isles of Scilly in
1995 (Holyoak 1996), and found on a total of four islands in
Scilly and two additional islets by 2003. The plant apparently
spreads freely by spores, so it was suggested that it may have
colonised the Isles of Scilly naturally, or at least spread
freely of its own accord after becoming established within the
islands. Its northern range limit elsewhere was then thought
to be at Isle d'Oléron on the Atlantic coast of France, but
the species is widespread in Mediterranean countries of Europe
and in the Azores, Canary Is. and on Madeira (Holyoak 1996).
However, a 1964 gathering from Sussex was belatedly reported
by Een (2004) and Matcham et al. (2005) cited
reports of it also from E. Cornwall, Belgium (de Beer &
Arts 2000), The Netherlands (van Zanten 2003) and SW. Ireland,
to which Bosanquet (2006) has added S. Wales (Pembrokeshire).
By 2006 there were two records from vc2 and two from the
mainland of vc1. Despite the suggestion by Matcham et al. (2005) that it
might be an overlooked native in Britain, the evidence seems
to imply rapid colonisation of NW. Europe in the past
few decades.
The species grows as flat patches (small to rather
substantial), creeping on the substrates. By 1996 it had been
found by DTH at a total of seven sites in the Isles of Scilly,
four on Tresco and three on St Mary's, all in groves of pines.
It appeared mainly to occur on or under old Pinus radiata (six
records) being recorded only once on P. contorta, the trees
of which are mainly younger. S. substrumulosum grew
mainly on bark of the pines, on leaning or horizontal trunks
(to 1.5 m above ground), low branches, old logs lying on
ground, or exposed roots, in lightly or moderately shaded
places. One record was from dry peaty soil overlying granitic
rock on a bank in shade of pine trees. Close associates were
often lacking, but those recorded were Hypnum cupressiforme
var.
resupinatum,
Lophocolea bidentata and Lophocolea
semiteres.
Several records of small patches made in 2002 and
earlier years by RAF differ in being from humic or peaty soil
far from any trees (at NW. end of White Island at mouth of
small N.-facing hole about 50 feet up from the sea on a
N.-facing grassy slope; on Gugh and St Agnes on soil partly
shaded by boulders or at burrow entrances on cliff slopes and
coastal heaths). DTH made similar finds in April 2003 at the
eastern end of St Martin's and on cliffs at Peninnis Head, St
Mary's. It is unclear whether these records represent further
expansions of the range of the species in Scilly or small,
inconspicuous patches that were formerly overlooked. A strong
impression gained by DTH is that many of the patches represent
initial stages of establishment, presumably from spores or
gemmae, that are unlikely to form mature colonies in these
apparently unsuitable habitats.
On Cornish mainland, recorded twice on Lizard pen:
on sloping stem of Gorse in an open roadside hedgerow, a small
patch growing with Frullania dilatata, Hypnum cupressiforme
var.
resupinatum and lichens in a rather nondescript and
ordinary location. Also in small quantity with Hypnum andoi on dead
stump of Lawson's Cypress in edge of conifer plantation. Two
more recent finds by JAP were in
churchyards.
Protonemal gemmae have recently been reported from
the species in the wild and in cultivation (J.G. Duckett in
Matcham et al.
2005). They are also numerous on the protonemata of a specimen
from Scilly (DTH 03-407) that consists of
tiny prostrate stems 3-5 mm long surrounded by a small mat of
protonema covering the surface of humic soil. A few similar
gemmae are also present low on the stems, arising from leaf
axils or on the stem surface. The gemmae are uniseriate,
cylindrical, translucent, typically of 5 or 6 cells and
measuring 109-151 × 25-34 µm, with blunt apical
cell, truncate base [of abscission cell] and rather rough
surface.
Commonly c.fr.: capsules immature 6, 8, 9;
dehiscing 8, 9; dehisced 6, 9.