*1: Stone in stream
below Trelowarren Mills, Mawgan, near Helston, May 1962, JAP
(BBSUK) (Warburg 1963b:
501, Paton 1969a: 747).
*2: Camel R., Dunmere,
1879, RVT (B) (Paton 1969a:
747).
Probably not a valid species: see notes
under H.
varium.
Grows as patches or wefts. Habitat notes
from Cornwall are as follows. On rocks and thin soil over
horizontal rocks (slaty) near and at water level (always in
flood-zone) beside large stream and rivers, part shaded by
deciduous trees. Thin silt/soil on rocks in flood-zone beside
R. Tamar, part shaded by deciduous trees. On slate rock
shallowly submerged in clean flowing water of large stream;
almost unshaded (Rocky
Valley).
Associates include Aneura pinguis, Sciuro-hypnum
plumosum, Fissidens
pusillus, Hygrohypnum ochraceum,
Platyhypnidium
riparioides.
Not seen c.fr.