*1: Small stones in
flush near stream, wooded valley, Castle Horneck, Penzance,
Aug. 1961, JAP (BBSUK) (Warburg 1963b: 493 as
F. minutulus var. minutulus, Paton
1969a: 712). [F. pusillus var. pusillus listed as
confirmed for vc1 by Corley 1980: 208, but without any
details].
*2: Stones in stream,
valley S. of Trecarrell Bridge, S. of Launceston, 1961, JAP
(BBSUK) (Crundwell 1968: 631, Paton 1969a:
712), as F. minutulus var. minutulus. [F. pusillus var. pusillus listed as
confirmed for vc2 by Corley 1980: 208, but without any
details].
Not consistently distinguished from allied spp. in
Britain until the
study by Corley (1980), when it was recorded
for vc1 and vc2, so that older records are accepted only when
specimens have been revised subsequently. Nevertheless, F. pusillus is often
difficult to separate from F. viridulus, the shape
of the leaf apex appearing to be an unstable character.
Indeed, the habitat appears more distinctive than the
morphology, so that populations of plants occur that are
recognisable as F. pusillus only or
mainly by the habitat (rocks in and near water), suggesting
that recognition of two taxa may have little value. F. pusillus can also be
very similar to diminutive plants of F. bryoides var. caespitans and F. crassipes and it
occasionally grows intermixed with those species. Plants
showing all characters of F. pusillus s. str. except that the
capsules were all somewhat inclined were found SW. of
Treswigga and SW. of Rosecraddoc Manor (DTH
07-473). See also notes below under F. bryoides var.
caespitans.
Grows as scattered plants or low open lawns.
Habitat notes from Cornwall are as follows. On horizontal,
inclined and vertical surfaces of stones and rocks (including
granitic and slaty lithologies), mainly from shallowly
submerged to within ca 15 cm above
water-level of streams. Normally in places that are lightly to
moderately shaded by banks, scrub or trees, including streams
in woodlands. Associates include Hygroamblystegium
fluviatile, Chiloscyphus
polyanthos, Platyhypnidium
riparioides. On granitic boulders in inundation zones at
edge of Argal Reservoir and Siblyback
Lake
(Reservoir), unshaded to lightly shaded, often with F. bryoides var. caespitans (q.v.). One record from
higher above water-level on flat rock near a sluice at
Clowance (vc1).
Commonly c.fr. [not recorded without well-grown
capsules]: capsules immature 2, 7, 10, 11; dehiscing 1, 7-11,
dehisced
10.
