Jennings: Manual of Mosses — 3. Leucobryaceae 67 



large parenchymatous outer cells 2-6-layered; lamina mostly narrow, often 

 vanishing below the apex, without a border; perichaetial leaves half-sheathing 

 and long-acuminate: seta terminal, or lateral by the growth of innovations, 

 long; capsule more or less arcuate, unsymmetric, often strumose, with 8 rib- 

 like projecting ridges; peristom.e on the edge of the urn, the teeth united at 

 base into a tube, cleft to the middle into two lance-subulate prongs, thickly 

 trabeculate, vertically striate and papillose; operculum subulate from a conical 

 base; calyptra inflated, cucullate, covering the urn. 



About 100 species, mostly in the tropics, on trees, rocks, or on shaded 

 earth; 8 in North America; 2 species in our range. 



Key to the Species 



A. Leucocyst on the median line in 3 to 4 layers; leaves 3 to 9 mm long: capsules arcu- 

 ate, strumose 1. L. glaucum 



A. Leucocysts on the median line m 2 layers in 4 to 14 series; leaves 1 to 4 mm long: 



capsule almost erect, not strumose 2. L. albidiim 



1. Leucobryum glaucum [Linnaeus] W. P. Schimper 

 {Dicranum glaucum Hedwig) 



Pincushion Moss — White Moss 



Plate XIV 



In dense, rounded, spongy, whitish or glaucous tufts, often 6 or 7 cm deep, 

 only the upper 5 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 som.ewhat more than halfway dov/n, acute, entire, ovate-lanceolate, 

 narrowed at base, erect-appressed, consisting almost wholly of the broad, thick 

 costa, the lamina extending 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, oblong-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 Mississippi 

 River. Common in our region, especially preferring the somewhat acid soil of 

 exposed white oak wooded upper slopes, often thus associated with Kalmia 

 and some of the wild huckleberries. 



Now known from 19 counties in western Pennsylvania and probably occurs in all. 

 Specimen figured; Barrens, Scotia, Centre County. Sept. 23, 1909. O.E.J. 



2. Leucobryum albidum [Bridel] Lindberg 



(/,. minus Hampe; Dicranum albidum Bride!) 

 Much smaller than L. glaucum: tufts very dense, about 1-3 cm deep; leaves 

 acute, narrower, shorter (about 1-4 mm long), closely imbricated and but little 



