HEW PHYTOIiOGIST. 
Vol. XIII, Nos. 6 & 7. June & July, 1914. 
[Published July 28th, 1914.] 
XEROPHYTIC ADAPTATIONS OF BRYOPHYTES 
IN RELATION TO HABITAT. 
By W. Watson, B.Sc. 
[With Three Figures in the Text.] 
(continued from p. 169). 
(e) Cuspidate Tufts. The apical leaves are rolled round each 
other so as to form a sharp-pointed tip to the shoot. Wheldon (25) 
says that “ many tufted mosses growing in open places have long- 
pointed leaves which in dry weather are closely appressed to the 
stem, the cuspidate apices of which present themselves as foci for 
the condensation of dew which drains down the stems, some being 
retained in the concavity of the leaves.” This character is not 
confined to xerophytes, in fact, the plant ( Hypnum cuspidatum) in 
which it is most prominent is usually a plant of marshy places, 
but by no means always so, as I have found it on dry limestone 
rocks and walls, probably where surface water occasionally over¬ 
flowed. This dry ground form scarcely differed from the marsh 
one except that the colour was darker, the cells narrower, and the 
cuspidate tips more tightly twisted than usual. Cuspidate tips are 
also well shown in H. aduncum v. pungens and in forms of some 
other Hypnum spp. 
(/) Leaf Squarrose in the Moist State. This appears to have 
little relation to xerophily, since most plants in which it appears 
are mesophytic or hydrophytic. Tortula ruralis, which grows on 
roofs and walls, has squarrose leaves, but it also has hair-points, 
spiral twisting, recurved margins to the leaves and papillose cells. 
Other squarrose-leaved plants with a xerophytic tendency are 
T. ruraliformis , Barbula recurvifolia , Weisia squarrosa, Pleurochcete 
squarrosa, Grimmia subsquarrosa, Brachythecium reflexutn and 
Hypnum Halleri. On the other hand Hylocomium squarrosum, 
Hypnum Sommerfeltii , Eurynchium prcelongum and its variety 
