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Photo
by Dr M Lueth ©.
*1:Trevaylor Valley, Penzance, 1866, WC (PNZ) (Paton 1969a: 745).
*2: St Cleer, RWS (in MEC Section II Report
1922 CHECK ); near Lesnewth, 1961, JAP (BBSUK) (Paton 1969a:
745).
Usually distinct from var. heteropterum in its
smaller size, with stem leaves no larger than branch leaves.
It was treated as a distinct species by Smith (2004), but
occasional specimens
appear to consist of slender var. flaccidum growing from
otherwise typical var. heteropterum, so the
former may consist only of weak shaded forms of the
latter.
Grows among other bryophytes or forms small low
mats. Notes on habitats in Cornwall are as follows. Apparently
differs from var. heteropterum in
sometimes occurring in habitats that are at least moderately
basic (although not conspicuously so in Cornwall) as well as in acid
sites, sometimes in drier places, and in being confined to
shaded sites. Grows on rock (granitic, slates, serpentinite,
gabbro; on steep or vertical surfaces, under overhangs and on
boulders; once on old masonry), less often on thin soil over
rock or firm soil of a steep bank; its sites are shaded or
heavily shaded by woodland or scrub. Recorded from rock
outcrops, boulders, rocks on slopes above streams and rivers
(occasionally within the flood-zone), old walls (twice), an
old quarry, a water-mill and at base of crag on slope above
sea-cliffs. Associates recorded are Kindbergia
praelonga,
Oxyrrhynchium pumilum, Lejeunea lamacerina,
Lophocolea
fragrans, also noted as growing under overhanging Dryopteris
affinis.
Not seen c.fr.
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