HYPNACEAE 83 



conclusively that no single character can be relied upon for the 

 purpose of classification but that all characters must be taken 

 into consideration. 



The leaf cells in this genus are narrowly linear, frequently 

 papillose at the back of the leaf by the thickening of the angles 

 of the cell walls as in Bryhnia, comparatively little differentiated 

 at base and angles, usually somewhat shorter and broader and 

 often colored. Our species are dioicous; capsules large, short, 

 inclined and unsymmetric, much as in the Brachytheciae: peri- 

 stome perfect with well-developed cilia. 



Key 

 1 — Paraphyllia lacking 2 



Paraphyllia present, usually very abundant 3 



2 — Stem leaves not plicate, strongly squarrose-recurved squarrosum 



Stem leaves plicate, widely spreading but not recurved triquetrum 



3 — Plants regularly and closely bi-tri-pinnate proliferum 



Plants rather irregularly branched brevirostre 



H. brevirostre (Ehrh.) B. & S. "Deep shaded ravines and 

 swamps. Sterile in N. J.," Muse. App. 448; Little Falls, N. J., 

 Austin, Bx! 



H. proliferum (L.) Lindb. (H. splendens B. & S.). Rare. 

 " Northport, Sanial," Flora L. Id. "On the ground in woods, 

 northern N. J.," Muse. App. 447. Spring. 



H. squarrosum (L.) B. & S. Hamden, Bry. Ct. 



H. triquetrum (L.) B. & S. New Lots and Partegat (27226), 

 Brainerd, and Northport, Sanial, on L. Id. "Common, sterile in 

 N. J.," Muse. App. 449; Kreischersville, S. Id., Hollick and 

 Britton, Bx!, "Four Corners," Mosses S. Id. Winter— spring. 



RHYTIDIUM (Sull.) Kindb. 



R. rugosum (L.) Kindb. Dry bluffs and ledges. Palisades, 

 N. J., Austin, Bx.!; "Common, sterile," Muse. App. 450. 



Subfamily Brachythecieae 



Hypnaceous mosses differing but little in general appearance 

 from many of the Hypneae, nearly always more or less glossy. 

 The leaves are straight and imbricated when dry, occasionally 



