THE POLYTRICHACE^ OF WESTERN NORTH AMERICA 



311 



2. Polytrichum attenuatum Menz., in Trans. Linn. Soc. (1798), 



p. 72. 

 Polylrichum conorhyncJmm Kindb., in Mac. Cat., p. 164 (1892). 

 Polytrichum for mo sum Hedw., in Sp. M., p. 92 (1801). 



Name derived from attenuatus = drawn out; referring to the 

 long narrow, simple form of the plant often found. 



Plants loosely tufted, dark green, 7-20 cm. high. Stems erect or 

 ascending, tomentose at base, simple or forked. 



Fig. 19. Polytrichum attenuatum. 

 1 = Moist plant with capsule, X i. 2 = Dry plant, X i. 3 = Capsule, X 5. 

 4 = Peristome, X 150. 5 = Leaf showing lamellae on upper side, X 15. 6 = Leaf 

 tip, X 65. 7 = Cross section of leaf showing lamellae ,X 65. 8 and 9 = Cross sections 

 of a few lamellai showing height and the marginal cells, X 250. 



