FLORA OF OXFORDSHIRE. 4II 
TORTULA, Hedw. 
Barbula, Br. & Sch. 
T. cavifolia, Ehrh. (Pottia.) 
On walls capped with mud. Winter. One of the characteristic mosses 
_ of this and the neighbouring counties, occurring in great profusion wher- 
ever the walls have been capped with the oolitic mud from the roads, but 
requiring fresh soil it is seldom constant to a place beyond one season. 
T. lamellata, Lindb. 
Pottia cavifolia, 5, gracilis, Wils. Bry. Brit. 
In similar situations to the last, but rather less frequent. Distinguished 
by its greater height and more tufted habit. October to February. 
Bicester; Noke ; Wheatley ; Witney ; Iffley, etc. 
T. rigida, Schultz. 
T. stellata, Braith. Moss-Flora. 
In similar situations to the last two. Winter. More robust and with a 
conspicuous strongly twisted, bright scarlet peristome. In very wet 
summers it appears as early as August, but generally not till: November. 
Salford; Charlbury; Witney ; Noke; Headington; Wheatley; Bampton; 
Standlake. Berks and Bucks, 
T. ambigua, Br. & Sch. 
In similar situations, and often growing in company with the last; also 
descending the sides of walls with T. muralis. Winter. A little larger 
than rigida, the capsule quite cylindrical, the peristome shorter and less 
twisted, the calyptra scarcely descending below the lid. 
T. aloides, Koch. 
Old turfy walls and embankments, gravelly banks, and on clay. 
Winter. Not so frequent as the last two about Oxford. Habit more 
tufted, leaves more acute pointed, capsule inclined. Islip and Noke; 
Kirtlington ; Ditchley; Rose Hill; Shotover Plantations. More frequent 
in the Witney district; Hailey, etc. 
T. unguiculata, Hedw. 
Gravelly banks, old walls, etc., very common and somewhat variable. 
Winter. Var. obtusifolia, canal bank near Wolvercote. 
T. fallax, Hedw. 
Walls, banks, broken ground either clay or calcareous; not very com- 
mon, and rare in fruit. Varies much in size and habit. Winter. Near 
Islip and Bicester; railway bank between Witney and Bampton; sides of 
drains at Stow Wood; Bullingdon; Shotover Hill. Var. brevifolia, 
gravel-pits near Bagley Wood and near Faringdon, Berks. 
