*1: Nancledra, 1962,
JAP (Paton 1969a: 752). [Porthmeor, 1924, PWR (Rilstone 1949)
not supported by specimen].
*2: Stones in R. Fowey,
Treverbyn, near St Neot, May 1961, JAP (Warburg 1962: 375,
Paton 1969a: 752).
Grows as low patches (smooth mats) or when large
forms short wefts. Habitat notes from Cornwall are as follows.
On low rocks (base-poor: granitic, slaty; occasionally
extending onto tree roots or dead wood close by), in and
beside streams, from just below to not far above normal
water-level (mostly within 0.2 m, occasionally 0.5 m; always
within flood-zone). Sometimes in open sites, more often partly
to moderately shaded e.g. by deciduous woodland, groves of
trees or Grey Willow carr. Records are mainly from small
quick-flowing streams of soft water, including small streams
near a spring and on a cliff top, but also found in trickling
water by an old mill and occasionally along larger rocky
rivers.
Often without close associates; other species
occurring close by include Fontinalis squamosa, Scapania undulata. Platyhypnidium
riparioides was recorded with or adjacent to it at three
sites; at Seworgan P. lusitanicum tended to
form a clearly marked higher zone (0-0.5 m above water) on
streamside rocks than accompanying R. riparioides (which
was often submerged).
Three records c.fr. (vc1): capsules immature 8, 10;
dehiscing 2 (capsules
pentiful).
