168 American Midland Naturalist Monograph No. 6 



On earth in moist woods, Alaska to Labrador, south to Missouri and 

 Alabama, also in northern Europe. 



Common in old fields, open woods, etc., esfsecially on peaty soil and clay hummocks 

 in the northern and upland counties, where it forms dark patches. Now known from 26 

 counties in western Pennsylvania and probably occurs in all. Specimen figured: Ohio 

 Pyle, Fayette Co., Sept. 1-3, 1907. O.E.J, and G.K.J. 



3. PoLYTRlCHUM PILIFERUM Schreber, Hedwig 

 Plates XXXII, LXIV 



Rather loosely cespitose, light green, rather glaucous: stems simple, erect, 

 1-4 cm high, purplish-brown, radiculose slightly at the base, leafy only in the 

 upper 1 cm or thereabouts; leaves when moist ascending, when dry imbricate- 

 appressed, base hyaline, rounded-oblong, about 1.5 mm long, the limb narrowly 

 lanceolate, about 3 mm long with wide margins inflexed and in the upper part 

 meeting or overlapping, the apex abruptly terminating in a hyaline, linear, 

 dentate arista about 1 mm long; costa wide, with about 25-35 lamellae ven- 

 trally, dorsally more or less papillose or dentate; lamellae usually of 4-7 cells, 

 the terminal one slightly wider and apically abruptly elongate; leaf-cells in 

 alar region of sheathing base quadrate to rectangular or hexagonal, hyaline, 

 slightly incrassate, in middle of sheathing part larger, rectangular, about .015- 

 .018 X .030-.040 mm, somewhat brownish-pellucid, incrassate, at base of limb 

 abruptly passing into rather opaque or brown-pellucid, much incrassate, 

 rounded cells, about .010-. 015 mm in diameter, in reflexed margin of limb 

 larger and irregularly obliquely rhombic: seta about 2-3.5 cm long, erect, flexu- 

 ous, 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 almost the whole 

 earth. In North America ranging from the Arctic regions south to California. 



Erie Co.: On sand-plain, Presque Isle, Sept. 20-22, 1906. O.E.J. Fayette Co.: 

 Upper Cucumber Run, Ohio Pyle, June 23, 1935. C.M.B. (Plate LXIV) McKean 

 Co.: Bradford, Dec. 23, 1896. D.A.B. (Plate XXXII) Washington Co.: Near 

 Washington. Linn & Simonton. (Porter's Catalogue). 



4. POLYTRICHUM JUNIPERINUM Willdenow, Hedwipr 



Juniper Hair-Cap Moss 



Plate XXXIII 



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 crenulate and inflexed, the costa strong and 

 excurrent into a reddish dentate arista; cells at base of sheathing portion of 



