Jennings: Manual of Mosses — 31. Hypnaceae 269 



12. Stereodon tenuirostris (Bruch and Schimper) Brotherus 



(Sematophyllttm temthostTe E. G. Britton; Hypnum cylindrocarpum 

 C. Mueller; Rhaphidostegmm cylmdricarpum Jaeger) 



Plate LI 



Flatly and broadly cespitose in thin intricate mats, slender: stems prostrate, 

 reddish, or green, pinnately branched, branches few, slender; stem-leaves sub- 

 lustrous, about 1.5 mm long, falacte-secund but not complanate, narrowly 

 lance-oblong, non-decurrent, acuminate, concave, apically serrate, marginally 

 somewhat refle.xed to the base of the acumen; median leaf-celLs linear-prosen- 

 chymatous, the apical usually a little larger, the alar few in number, inflated, 

 sub-quadrate, bordered above by a few small quadrate, sub-opaque, often 

 transversely elongated cells; branch-leaves similar to the stem-leaves, some- 

 times a little larger; costa very short and double or none; perichaetial leaves 

 erect, the inner plicate and gradually narrowed to a very slender serrate point, 

 with a very short and double costa or none: seta about 5-7 mm long, sinis- 

 trorsc above, lustrous, castaneous; capsule cylindric to lance-oblong, the urn 

 about 1-1.5 mm long, erect to somewhat inclined, symmetric; annulus no.ne; 

 e.xothecial cells somewhat collenchymatous, brownish, oblong-rectangular, the 

 upper 3 or 4 rows rounded-quadrate; peristome-teeth yellowish, lance-subulate, 

 finely cross-striolate, strongly trabeculate, the dorsal lamellae projecting to 

 form a rather conspicuous hyaline border; segments about thre;-fourths as long, 

 slender, carinately split between the articulations, the basal membrane about 

 one- third as high as the teeth, cilia none or very rudimentary; lid conic and 

 with a slender rostrum about one-half as long as the urn; spores in late fall 

 to early spring, about .014-. 018 mm, smoothish, brownish, rather thinly in- 

 crassate. 



On rotten logs and bases of trees and on rocks in dark woods, in the moun- 

 tains from North Carolina and Georgia north to New York and Indiana. 



Allegheny Co.: Wildwood Road Hollow, side of ravine under dense shade of 

 hemlocks, November 19, 1908. O.E.J. Cameron Co.: On wet rocks 3 mi. w. of Tru- 

 man. June 22, 1935. Sidney K. Eastwood. Fayette Co.: On rock in shaded woods in 

 valley of Meadow Run, four imles south of Ohio Pyle, September 1-3, 1906. O.E.J, and 

 G.K.J. Westmoreland Co.: "Shades," near Blackburn, March 25, 1910. O.E.J, and 

 G.K.J, (figured). 



20. IsoPTERYGiUM Mitten 



Autoicous or dioicous: mostly slender to verv slender, cespitose. soft, 

 mostly bright or yellowish-green and glossy: stem creeping to ascending, up- 

 right only in the thick mats, mostly irregularly branched; leaves uniform, most- 

 ly complanately and obliquely inserted, smooth, usually more or less two- 

 seriate, from a narrow and little or not at all decurrent base oval to oblong 

 and short-pointed or else ovate to lance-oblong and acute to piliferous, margins 

 plane and entire to serrate; costa double, very short, or none; cells prosen- 

 chymatous, smooth or papillose in the upper angle, the basal shorter, the alar 

 not usually differentiated: seta long, sm.ooth, mostly drying twisted; capsule 

 sub-erect to cernuous or horizontal, with a collum, oval to oblong or cylindric, 



