*1: Near Black Head,
Coverack, 1962, ACC (Paton 1969a: 736).
*2: Gunwen near Bodmin,
1878, RVT (B) (Paton 1969a:
This species was poorly understood before the
revision by Crundwell & Nyholm (1964); older records are
given only where determinations of old specimens have been
revised more recently.
Habitat notes from C&S are as follows. Usually
recorded on mortar, crumbling mortar or concrete, of walls
(including those of modern reservoir dam, ruined mine
buildings, church and old bridges), blocks of concrete debris,
unshaded to lightly shaded (and not infrequently also more
heavily shaded in deep crevices in masonry). Also on thin soil
in crevices of old walls and on old bricks, occasionally on
deeper free-draining soil on banks. Associates commonly
Didymodon rigidulus, Didymodon
Orthotrichum diaphanum, Schistidium
Tortula muralis, sometimes Bryum donianum, Didymodon luridus, Gyroweisia tenuis, Hypnum cupressiforme
Pseudocrossidium revolutum, Tortella nitida, Trichostomum
Rhizoidal tubers often rather sparse.
Commonly/frequently c.fr.: capsules immature 1-6 (7), 11, 12;
dehiscing ; dehisced [1, 4, 7 old]