OF WESTERN PENNSYLVANIA 119 



2. Orthotrichum lescurii Austin. 

 (O. cnpulalHin variety minus SuUivant). 

 (Plate XV) 

 Rather densely cespitose, about 5 mm. high : stems thickly- 

 foliate, branched ; leaves lanceolate or some of the lower ovate, 

 the upper about 3 mm. long, the lower shorter, acute, the mar- 

 gins entire, revolute, strongly costate nearly to the apex ; basal 

 leaf-cells quadrate to elongate-rectangular, smooth, hyaline, 

 above becoming rounded-hexagonal, sub-opaque, densely 

 papillose, smaller and quite regularly hexagonal at the apex; 

 seta very short, 0.5 mm., about one-half enclosed in the in- 

 volucre; calyptra narrowly campanulate, plicate, hirsute with 

 erect hairs ; lid mamillate, rounded but flattened ; capsule ob- 

 long-cylindric and rather suddenly tapering to the seta, about 

 1.3 mm. high and 0.5 mm. in thickness, when moist globose- 

 oblong and 8-striate, when dry deeply 8-furrowed and some- 

 times contracted below the mouth ; capsule always about the 

 same length as the upper leaves, or sometimes slightly exserted 

 when dry ; peristome single, the teeth 8, short, equidistant but 

 leaning towards each other in pairs, triangular-lanceolate, 

 papillose, articulate, the divisural usually complete and not 

 split, teeth when dry erect or incurved ; spores mature in 

 spring, .014-.017 mm. 



On rocks, usually granite or trap ; from New England to 

 Ontario south to Missouri and Pennsylvania, and in the Rocky 

 Alountains to British Columbia. Rare in our region. 



Westmoreland : On sandstone rocks at mouth of Bear's 

 Cave, on slope of Chestnut Ridge above 

 Hillside, September 16, 1910. O. E. J. 

 and G. K. J. (Figured). 



3. Orthotrichum braunii Bryologiae Europae. 

 (0. sirangtdatii'in Sullivant). 



(Plate XV) 

 Sparsely cespitose to scattered, less than 5 mm. high, dark 

 green: stems sometimes creeping at base, erect-spreading, 

 simple or branched ; leaves spreading when moist, the upper 

 somewhat clasping, when dry appressed, not crisped, concave, 

 ovate to lance-ovate, the margins more or less revolute, apex 

 acute, sometimes erose-denticulate and apiculate and some- 

 times hyaline ; costa strong, sub-percurrent basal leaf-cells hya- 

 line, smooth, at margin quadrate, about .016 mm. in diameter, 

 toward the costa rectangular and reaching about .090X-016 

 mm., median cells papillose, opaque, rounded, about .020 mm. 

 in diameter, the apical smaller, rounded and less papillose; 

 capsule oblong-oval, about 1.2 mm. long tapering abruptly into 

 a seta about one-third as long, 8-costate, when dry much con- 



