Jennings: Manual of Mosses--34. Brachytheciaceae 297 



basal membrane one-third to two-ftfths as high; ciha 2 or 3, nodose, hyaHne, 

 somewhat shorter than the segments; hd conic-acuminate, about 0.5-0.8 mm 

 long; annulus large; spores mature in winter, faintly roughened, medium- 

 walled, brownish, .013-.016 mm in diameter. 



On earth, rocks, bases of trees, rotting wood, etc., in rather dry woods, 

 often on knolls; Europe, Asia, and from Canada south to New Jersey and 

 Pennsylvania and also in the Pacific States. 



Thus far reported but once in our region. McKean Co.: Langmade, near Bradford, 

 April 25, 1898. D.A.B. (figured). 



11. Brachythecium populeum (Hedwig) Bryologia Europaea 

 (Hypnum populeum Hedwig) 



Slender, densely cespitose in small yellowish-green tufts, lustrous: stems 

 procumbent, branched with numerous, more or less pinnately-arranged, erect 

 or curved-ascending branches; leaves of stem and branches similar e.xcept that 

 the branch-leaves are narrower and lanceolate; stem-leaves rather closely imbri- 

 cated, erect to erect-spreading when dry, ovate-lanceolate, serrate to nearly 

 entire, slenderly and gradually acuminate, non-striate, shortly decurrent; costa 

 strong and reaching the apex; median le=>-f-cells about 5-8:1, sometimes rela- 

 tively longer, the basal more or less rectangular, the alar numerous, often 

 yellowish but rather opaque; seta rough except towards the base, where nearly 

 smooth, dark brown; annulus persistent, simple, narrow; capsule about 2:1, 

 cernuous, turgid-ovate to ovoid, mostly dorsally gibbous, glossy, constricted at 

 the mouth when dry; lid shcrt-acuminate; peristome norm.al, cilia short, usually 

 1 or 2 and unequal, appendiculate; spores mature in winter; autoicous. 



On roots of trees, stones, sometimes on bases of trees, in shadv woods, said 

 to be somewhat partial to pine woods; Europe, northern Africa, and from 

 Nova Scotia to North Carolina and in British Columbia. 



Rare in our region. McKean Co.: "B. populeum rufescens." Bradford. D.A.B. 

 (Porter's Catalogue). 



12. Brachythecium flagellare (Hedwig) Jennings 



{Hypnum flagellare Hedwig; Hypnum plumosum Swartz; 

 B. plumosum (Sw. ) Bryologia Europaea) 



Plate LVII 



Robust in loose, wide, green mats, brownish below: stems prostrate, up to 

 5 or 6 or more cm long, with rather densely pinnate branches; the branches 

 j-tout, ascending to erect, somewhat tumid with the closely imbricate, concave 

 leaves; leaves crowded, erect-spreading when moist, imbricated when dry, often 

 quite strongly falcate-secund, the branch-leaves lanceolate to broadly lance- 

 ovate, abruptly slenderly acuminate, about 1.3-2.0x0.4-0.9 mm, decurrent, 

 serrate above to nearly entire, the base very concave som.ewhat excavate at the 



