62 



HANDBOOK OF MOSSES. 



groups, called tribes, and these tribes are formed by genera 

 having certain leading characters in common. 



Sub-group III. Bryaccea. 



SERIES I. ACROCARPI. Fruit terminal (fig. 4). 



Tribe I. Phascea. -Plants minute ; leaves soft ; leaf-cells 

 loose ; capsules globose (fig. 14), more or less enclosed 

 within the leaves ; fruit-stalk usually very short ; capsule 

 splitting irregularly. 



Comprising Phascum> Ephemerum (fig. 3), etc. 



FIG. 32. Barbula subulata. i, plant natural size. 2, upper portion of fruit: a, 

 capsule ; b, twisted peristome ; 3, leaf enlarged; 3 a, cells of upper portion of leaf. 



Tribe II. Weissiece. Plants tufted ; leaves with a single 

 nerve or vein ; leaf-cells opaque, dot-like, or quadrate 

 (square), often papillose (with minute protuberances) in the 

 upper part, hexagonal and more or less transparent in the 

 lower ; lid usually beaked ; peristome single or absent j 

 calyptra split on one side. 



This is a large group of mosses, including Weissia, Di- 

 cranum, Ceratodon, Selegeria, etc. 



Tribe III. Pottiea. Branches fastigiate by innovations 

 (i.e. having additional branches of an equal height) leaf-cells 



