66 A MAN'UAL OF MOSSES 



1. Oncophorus wahlenbergii Briclel. 

 (Plate VIII) 



Densely cespitose, light or yellowish-green above, darker 

 below : stem ascending or erect, forking, up to 3 cm. high, 

 sparsely radiculose below ; leaves numerous, dense, much 

 crisped when dry, abruptly flexuous-spreading when moist, 

 from a concave, widely obovate base abruptly contracting into 

 a long, carinate, linear-subulate, flexuous, rather acute portion 

 which is low-serrate at the apex both marginally and dorsally ; 

 costa strong, ending in the apex ; leaf-cells at base mostly 

 pellucid and obliquely elongate-rectangular, about 3-10:1, 

 above at the shoulder and along the subulation quickly be- 

 coming much smaller, incrassate, about .005-.007 mm. in 

 diameter, smooth, sometimes faintly rounded papillose : seta 

 single, erect, flexuous, yellowish to brownish, when dry 

 strongly dextrorse, 1-1.5 cm. long; capsule about 1.2 mm. 

 long, arcuate-cernuous, oblong-cylindric, gibbous, distinctly 

 sharply strumose, when old irregularly wrinkled ; peristome- 

 teeth united at base into a rather deeply inserted tube, the 

 teeth divided to the middle, lance-linear, castaneous-pellucid, 

 very faintly dorsally articulate below, strongly ventrally 

 trabeculate in a double series separated by a more or less zig- 

 zag divisural line, at the base smooth, towards the middle 

 minutely vertically striate-papillose, at the apex sub-hyaline ; 

 annulus narrow with crenulate margin ; operculum obliquely 

 rostrate ; exothecial cells irregular, rather lax, with medium 

 walls, not much different towards the mouth ; spores papil- 

 lose, castaneous-pellucid, about .02S-.030 mm., mature in 

 spring. 



On rocks, soil, old logs, etc., in cool and moist situations, 

 usually in the mountains in non-calcareous districts. Europe, 

 Asia, and, in North America, from Greenland to Alaska and 

 south to the northern United States. Rare in our region. 



McKean : Broadbow, D. A. B. 



10. DICRANUM Hedwig. 



Autoicous or dioicous; mostly large and thickly tufted, 

 often cushion-like : stems mostly erect ; leaves mainly falcate- 

 secund, more or less subulate-acuminate from a concave, 

 lanceolate base, and usually canaliculate to tubulose ; costa 

 largely excurrent ; alar leaf-cells mostly brownish and dif- 

 ferentiated ; inner perichaetial leaves elongate, involute-sheath- 

 ing, the acumen often short or lacking : seta erect, mostly 

 twisted, sometimes 2 to 5 together in a perich?etium ; capsule 

 various from cylindric and erect to cernuous and arcuate or 

 even rarely strumose ; operculum long-rostrate and by a dif- 

 ferentiated annulus always with a notched edge ; peristome not 



