38 MOSSES WITH A HAND-LENS 



Its capsules are strongly curved and cernuous ; they mature in 

 autumn. 



The Pinnate Hypnum is a much more common moss in the 

 lowlands and grows almost exclusively on rotten wood in moist 

 shady places. It somewhat resembles the Plume Moss, but is 

 prostrate, forming dense closely cohering mats. It is also darker 

 green; the capsules are nearly erect and symmetric, and the pin- 

 nate branching stops short of the apex of the shoots, as is shown 

 in the figure. A careful examination will show that there is a 

 difference in the curvature of the leaves; in the Pinnate 

 Hypnum the leaves curve towards the substratum at right 

 angles to the plane of the stem, while in the Plume Moss they 

 curve towards the branch next below on the stem. The capsules 

 of the Pinnate Hypnum are produced much the more freely; 

 they mature in winter, but persist in good condition for a long 

 time. 



Hypnum curvifblium Hedw. is a much rarer moss that re- 

 sembles H. imponens when sterile. It is more confined to the 

 mountains, is larger, lighter colored, and has curved cernuous 

 capsules that are very strongly furrowed when dry, looking much 

 like those of the Fuscous Dicranum (Fig. 7). 



Hypnum reptile Mx. is another regularly pinnate moss of 

 this group, but it is less than half the size of the three described 

 above. Its general appearance is fairly well represented in 

 Fig. 27, b, but the capsules are longer and more curved. With a 

 lens the leaves of the Thuidium will be seen to be acute and 

 straight, while those of the Hypnum are curved and long 

 acuminate. The Thuidium grows in thin mats so that its pin- 

 nate character is easily seen at a glance ; the Hypnum grows in 

 such densely interwoven mats that it is often necessary to disen- 

 tangle it before its pinnate character becomes apparent. Hypnum 

 reptile matures its capsules much earlier than any of the three 

 other species mentioned above. They are usually fully ripe in 

 August. 



Wherever rotten wood is found in moist shaded places, there 

 the Common Hypnum (H Haldanianum Grev. ) is almost sure to 

 grow, covering the unsightly masses of rotten wood with its up- 

 holstery of bright green. It is one of our commonest mosses and 

 nearly always fruits freely. 



