CATHARINEA. 33 



Polytrichum renders almost the whole surface dark green and 

 opaque : the lamellose-leaved species of the Tortulacese will be 

 readily distinguished by their small fruit, being usually fertile. 

 The leaves among the Polytrichaceas are among the largest, 

 especially in point of length, of any mosses. 



The stem in Polytrichaceae, as well as the seta, shows a 

 higher development than in any other order, there being a 

 specialised central axis, the tissue of which, both in anatomy and 

 function, shows an approach to the central fibro-vascular bundle 

 in the Vascular Cryptogams. An interesting discussion on this 

 and other points in reference to the Polytrichaceae by J. R. Vaizey 

 will be found in the Journ. of the Linn. Soc, Botany, Vol. XXIV, 

 p. 262, " On the Anatomy and Development of the Sporogonium 

 of the Mosses." 



The structure and function of the peristome and epiphragm 

 are of great interest, and the student is referred to the description 

 of these parts in Dr. Braithwaite's British Moss Flora, and in 

 Philibert's admirable papers on the peristome in the Revue Bryo- 

 logique. 



Besides the British genera, there are two exotic genera of 

 importance, Dawsonia and Lyellia. 



A useful synopsis of the European and North American 

 species of Polytrichaceae by N. C. Kindberg, will be found in the 

 Rev. Bry., 1894, pp. 33, sqq. 



4. CATHARINEA Ehrh. 



(Synonym, Atrichum P. Beauv., SchimperSyn., et plur. auct.) 



Stems moderately tall, leaves slightly embracing the stem 

 but not sheathing, nor narrowed above the base, Ungulate or ovate- 

 oblong, crisped when dry, bordered and serrate, generally 

 undulated, with few straight lamellas above. Calyptra glabrous, 

 spinulose-papillose at apex. Capsule smooth, oval or cylindric, 

 curved ; lid long-beaked ; peristome of 32 teeth, with a narrow 

 basal membrane. Inflorescence usually dioicous. 



,/Ls. narrow-lingulate, back of nerve and lamina spinose-toothed above 2 



\Ls. wider, oblong, lamina smooth at back ...... .J. crispa 



f Ls. obtuse, margin toothed in upper half only ; capsule suberect ; dioicous 



J 2. angustata 



J Ls. rather acute, margin toothed throughout ; capsule arcuate ; paroicous 



V. 1. undulata 



D 



