76 A MANUAL OF MOSSES 



Key to the Species. 



a. Leucocysts on the median line in 3 to 4 layers; leaves 3 to 9 mm. 



long: capsules arcuate, strumose. i. L. glaucum. 



a. Leucocysts on the median line in 2 layers in 4 to 14 series; leaves 



1 to 4 mm. long: capsule almost erect, not strumose. 



2. L. albiduiu. 



1. Leucobryum glaucum [Linnaus] \V. P. Schimper. 



(Dicranuin glancuui Hedwig), 



(Plate X) 



In dense, rounded, spongy, whitish or glaucous tufts, often 

 6 or 7 cm. deep, only the upper S mm. or thereabouts alive, the 

 dead inner portion grayish-brown and peaty : leaves crowded, 

 in our region about 3-6 mm. long, more or less tubular, acute, 

 entire, ovate-lanceolate, narrowed at base, erect-appressed, con- 

 sisting almost wholly of the broad, thick costa, the lamina ex- 

 tending about half-way up the leaf as a narrow margin of 

 2-5 rows of hyaline, thin-walled, long-rectangular to linear 

 cells: seta about 10 mm. long, sinistrorse, castaneous, erect; 

 capsule 1.5 to 2 mm. long, castaneous, when dry arcuate, ob- 

 long-cylindric, distinctly strumose, furrowed ; lid long-rostrate, 

 nearly as long as the urn; calyptra longer than the capsule; 

 peristome slightly inserted, deep reddish-brown, dicranoid ; 

 spores rather thin-walled, slightly roughened, .015-020 mm. 

 in diameter, slightly roughened, mature in autumn. Capsules 

 are produced infrequently. 



Almost cosmopolitan on soil or on rocks in woods. In 

 North America it occurs from Newfoundland to Florida and 

 westward to the Rocky Mountains. Common in our region, 

 especially preferring the somewhat acid soil of exposed white 

 oak-woods, often thus associated with Kalinia and some of 

 the wild huckleberries. 



Allegheny : Darlington Hollow, June 26, 1885. J. A. 



S. ; Coraopolis, September 4, 1905, O. E. 

 J. and G. E. K. ; Douthett, December 29, 

 1908, and under hemlocks, Darlington 

 Hollow, October 25, 1908. O. E. J.; 

 Stewart's Stop, Charleroi Electric R. R., 

 August 19, 1907. O. E. J. and G. K. J. 

 Armstrong : Kittanning, August 16, 1906. O. E. J. 

 Center : Scotia, in Barrens, July 14 and Septem- 



ber 23 (Figured), and Tussey's Mt., near 

 Shingletown, July 15, 1909. O. E. J. 

 Crawford : Pymatuning Swamp, on elevated hum- 



mock, Linesville, June 12, 1905, and May 

 12, 1908. O. E. J. 

 Erie : Presque Isle, June 9-11, 1905. O. E. J. 



