82 A MANUAL OF MOSSES 



4. Fissidens incurvus Starke, Schwaegrichen. 



Typically this species is about 2-6 mm. high, with rather 

 broadly oblong-lanceolate leaves, which are obtuse-apiculate 

 and narrowly bordered up to near the apex : seta reddish, long, 

 flexuous ; capsule oval-cylindric, curved and usually more or 

 less inclined or cernuous ; antheridial buds basal. 



On rocks, or more rarely clay, usually in shaded brooks 

 and ravines, America from Greenland to Vancouver Island to 

 Texas. Europe, Asia, Africa, New Zealand. 



Fayette : On muddy rock in bed of mountain rivulet, 

 Ohio Pyle, June 14, 1908. O. E. J. and G. K. J. 



McKean : Hunt's Run, April 28, 1893. D. A. B. 



In our region this species is rare in its typical form but is 

 represented by a form closely approaching, but perhaps not quite 

 typical, variety minutulus (Sullivant) Austin, as follows: 



4a. Fissidens incurvus variety minutulus (Sullivant) Austin. 



(/ ; . minutulus Sullivant). 

 (Plate X) 



Plants minute, 0.8-5.0 mm. high, gregarious, green, erect: 

 stem simple, reddish ; leaves 3-7 pairs, hardly imbricate, the 

 uppermost much larger and incurved-erect and up to 2.5 mm. 

 long, narrowly oblong-lanceolate, more or less acute, the 

 border narrow, ceasing below apex, widest at upper part of 

 sheath, margin entire or somewhat undulate, the sheath about 

 one-half the length of the leaf, the inferior lamina narrowing 

 at base but hardly decurrent ; costa strong, ending usually a 

 little below apex ; leaf-cells incrassate, more or less rounded to 

 hexagonal, rather irregular, the basal becoming rectangular, 

 the border consisting of 1-3 rows of elongate-linear or ascend- 

 ing prosenchymatous cells : seta reddish, smooth, erect, sub- 

 flexuous, about 3-6 mm. long; capsule usually erect, sym- 

 metric, 0.7-0.9 mm. long, yellowish to dark chestnut color, 

 oval-oblong, tapering abruptly at base : peristome rich red- 

 chestnut, the teeth deeply forked into two awl-like prongs 

 with prominent spiral thickenings, teeth slightly inserted ; 

 spores round to oblong, pellucid, pale yellow-red, smoothish, 

 .014-.017 mm. in diameter; operculum conic-rostrate. Mature 

 in early autumn. 



On damp stones and rocks, in shady woods or in stream 

 beds, Nova Scotia to Vancouver Island and south to Texas; 

 Europe. 



Allegheny : Schenley Park, Pittsburgh, August 20, 



1905, Darlington Hollow, November 9, 

 1908, Keown, November 14, 1909, and 

 Powers Run. November 30, 1909. O. E. J. 



