*1: Granite in disused china clay
works, in old quarry, Tresoweshill, 21 Mar. 1965 (including
specimens in BBSUK and OXF
named as M. ustulata) (Paton
1990a: 3, Long 1991: 38).
*2: With Marsupella sprucei,
unshaded, on near-horizontal surface of granitic boulder at
base of bank near quarry, S. of Treviscoe, SW95, 1998, DTH
98-71 (BBSUK, DTH) (Blackstock 1999:
37).
All British records are from Cornwall. Holyoak
(2010a) gives a summary of steps taken for conservation of the
species in Cornwall between 1990 and
2010.
It is a colonist, occurring in patches on clayey to
gravelly substrates on banks and flat ground in and around old
and working china clay quarries, unshaded or at most lightly
shaded; also on inclined to horizontal surfaces of granitic
boulders (less often on vertical or overhanging granite),
especially where crumbling and soft at surface (nearly always
with Marsupella
sprucei and Nardia
scalaris; other common associates include Cephaloziella
divaricata, Pogonatum urnigerum,
less often Dicranoweisia cirrata,
Marsupella emarginata
var.
emarginata).
Marsupella sprucei occurs at most sites where present species is
known and often they are closely intermixed. Overall, it
appears that M. profunda is
relatively commoner in more sheltered, humid places on
substrates that are more water-retentive, whereas M. sprucei extends on to
quicker drying substrates in more exposed
places.
Commonly cfr; capsules immature 11, 1-3; dehiscing
1-3; dehisced 3.
