98 A MANUAL OF MOSSES 



longed linear-lanceolate; with mostly revolute margins; costa 

 'strong, ending in the point, or excurrent ; leaf-cells very small, 

 thickened and opaque, papillose both sides; basal leaf -cells en- 

 larged, quadrate to rectangular, colored : seta long, erect ; 

 capsule erect, rarely a little inclined, oblong to cylindric, 

 straight or rarely a little arcuate; annulus distinct or none; 

 peristome rarely rudimentary, or none ; the teeth united below 

 into a rather low basal membrane which is rather deeply in- 

 serted, the 32 teeth spirally one to several times dextrorsely 

 wound, filiform ; operculum conic-rostrate ; calyptra cucuUate, 

 long-rostrate, reaching to about the middle of the urn ; spores 

 small. 



A genus of 240 species distributed over the whole earth, 

 on soil and rocks; about 70 species in North America; only 

 two species definitely known from our region. 



Key to the Species. 

 a. Perichaetial leaves high-convolute-sheathing: seta yellowish or 



later reddish. 3. B. convohita. 



a. Perichsetial leaves not as above: seta red or brown. 



b. 

 b. Stem-leaves obtuse, costa shortly mucronate-excurrent. 



2. B. ungiiiculata. 

 b. Stem-leaves acute, costa not mucronate-excurrent. 



c. 

 c. Costa .070 mm. wide at base and taperhig gradually. 



I. B. acuminata. 

 c. Costa .050 mm. wide at base and of equal breadth to the middle. 



(5. reflexa Bridel). 



1. Barbula acuminata Hedwig. 

 {B. fallax Hedwig). 



Loosely and widely cespitose, brownish dull green : stems 

 fastigiately branched, slender, 1-5 cm. high ; leaves some- 

 what distant, recurved-spreading or arcuate, appressed and 

 slightly twisted when dry, lanceolate-acuminate from the base, 

 the base ovate, the leaves carinate and often faintly plicate 

 below, the margin revolute in the lower half at least, entire; 

 costa strong, ending in the apex; upper leaf-cells small, 

 rounded to hexagonal, incrassate, strongly papillose, gradually 

 larger below, and at the lowest part of the base a few elongate- 

 rectangular and pellucid : seta reddish, capsule brownish, long- 

 ovoid to sub-cylindric, mostly symmetric and erect ; lid long, 

 often as long as the urn, acutely rostrate-subulate; peristome- 

 teeth reddish, long, filiform, dextrorsely much twisted, united 

 at base into a low membrane ; annulus none ; spores mature 

 from late fall to spring: dioicous. 



On moist earth, rocks, walls, etc., usually on calcareous 

 substrata, in Europe, Asia, northern Africa, and, in North 

 America from the Arctic region south to the northern United 

 States. To be expected in northern Pennsylvania. 



