OF WESTERN. PENNSYLVANIA 219 



or less undulate above, the margins entire or slightly dentic- 

 ulate; costa short and faint, more or less bi-striate and 

 wrinkled ; median leaf-cells linear at base, towards the apex 

 the upper marginal and apical broadly rhomboid; inner peri- 

 chsetial leaves entire, half-sheathing, elongate-lanceolate, reach- 

 ing somewhat beyond the capsule : seta very short ; capsule 

 immersed, yellowish, oblong-oval, brown when old, about 

 2.5 :1 ; lid acute-conic or acuminate ; calyptra very small and 

 covering only the operculum ; peristome double, teeth irregular- 

 ly divided, subulate-linear from a lance-linear base, sometimes 

 apically coherent, the segments rudimentary and very short; 

 spores in summer. 



On trees or on moist rocks in cool, moist woods, usually on 

 the trunks of deciduous trees; widely distributed in temperate 

 regions, in North America extending from lower Canada south 

 to North Carolina. Probably rather common in the eastern 

 part of our region. 



Cambria : Cresson. T. C. Porter. (Porter's Cata- 



logue). 



McKean : D. A. Burnett. (Porter's Catalogue). 



2. Neckera complanata [Linnaeus] Huebener. 

 {Hypnum complanatum Linnaeus; Homalia complanata De- 

 Notaris). 



Yellowish to pale green, in rather large and dense tufts, 

 soft : stems long, often reaching 8 or 10 cm., branchlets pinnate- 

 ly arranged ; complanate, sometimes more or less flagelliform ; 

 leaves oblong-lingulate, compressed, complanate, usually 

 rounded at the apex and short-apiculate, sometimes acute or 

 acuminate, those at the tips of the branches often more or 

 less deflected and falcate, the margin usually inflexed at base 

 on one side, serrulate at apex; costa double, very short and 

 faint, or none; median leaf-cells linear-vermicular, the apical 

 shorter and wider, rhomboidal, the angular quadrate-oval and 

 yellowish-pellucid; perichaetia borne along the sides of the 

 stem, the leaves long-sheathing : seta yellow, about 1 cm. long ; 

 capsule oval to elliptic-oblong, pale, orange-yellow or castane- 

 ous, about 2:1, small-mouthed; lid subulate-rostrate, usually 

 oblique; calyptra cucullate, reaching to about the middle of 

 the urn ; peristome-teeth long, pale, narrow, the segments about 

 half as long, filiform from an enlarged base ; spores mature in 

 spring but capsules rarely produced. 



On bark of trees, rarely on rocks ; Europe, Asia, northern 

 Africa, and from Labrador to Tennessee. Rare in our region. 

 Reported from "Allegheny Mountains in Pennsylvania" in 

 Lesquereux and James' Manual. 



