OF WESTERN PENNSYLVANIA 197 



regularly obliquely rhombic : seta about 2-3.5 cm. long, erect, 

 flexuous, lustrous, light chestnut-brown to paler above ; capsule 

 small, about 2-2.5 mm. long, tetragonal-oblong to almost cubic, 

 sharply angled, erect to pendulous, usually horizontal in age; 

 operculum shortly rostrate ; calyptra covering whole capsule ; 

 cells of exothecium hexagonal with a large oblong pore one- 

 half the diameter of the cell; peristome-teeth rather hyaline, 

 about 0.2 mm. high ; spores round, smooth, about .010-.012 mm., 

 mature in mid-summer. 



In dry, sandy soil, heaths, etc., in cooler regions over al- 

 most the whole earth. In North America ranging from the 

 Arctic regions south to the northern part of the Gulf States 

 and California. 



Erie : Presque Isle, on Sand-Plain, September 



20-22. 1906. O. E. J. 



McKean : Bradford, December 23, 1896. D. A. B. 



(Figured). 



\\ ashington : Xear Washington, Linn and Simonton. 



(Porter's Catalogue). 



3. Polytrichum juniperinum YVilldenow, Hedwig. 



(Plate XXIX) 



Rather loosely cespitose, erect, light green and somewhat 

 glaucous : stems slightly tomentose at base, in our specimens 

 about 5-9 cm. high, brown; leaves rather crowded, when 

 moist spreading, when dry erect-appressed, or in the older 

 stems somewhat spreading, the base oblong, sheathing, the 

 limb lance-linear, 5-6 mm. long, the margin entire or crenu- 

 late and inflexed, the costa strong and excurrent into a reddish 

 dentate arista ; cells at base of sheathing portion of leaf linear- 

 lectangular, mainly parenchymatous, moderately incrassate, in 

 middle portion of sheath relatively wider, about .010X-040-.090 

 mm., both prosenchymatous, in inflexed margin of limb 

 obliquely quadrate-rectangular-elongate, decidedly incrassate; 

 lamellae about 30-40, usually 6-7 cells high, the terminal cell 

 somewhat broader and with an abruptly narrowed shortly 

 prolonged apex ; perichsetial leaves more hyaline with a longer 

 sheathing base and a considerably longer slightly dentate 

 arista: seta erect, flexuous, lustrous, about 4-6 cm. high, some- 

 Avhat sinistrorse ; capsule tetragonal-oblong, about 3-5x2-2.5 

 mm., sharply angled, reddish to dark chestnut-brown when 

 old, apophysis short but rather distinct, capsule pendulous to 

 horizontal; spores round, smoothish, about .OOS-.011 mm., 

 mature in midsummer; cells of exothecium elongate-hexagonal 

 to quadrate-hexagonal, the perforation linear-oblong, about 

 half as long as cell. 



