220 American Midland Naturalist Monograph No. 6 



hyaline margin; segments about as long as teeth, carinately split, rising from 

 a basal membrane about two-fifths as high, the cilia 1 (sometimes 2 or 3), as 

 long as segments, slender, nodose to appendiculate; annulus 2-3-seriate; npores 

 papillose, when mature brownish or yellowish, medium-walled, about .014-. 018 

 mm, mature in spring: autoicous. 



On bases and roots of trees, decaying logs, soil, rocks, etc., in moist woods; 

 cosmopolitan; in North America occurring from the Arctic regions to the 

 Gulf of Mexico. 



Fairly common in our region. Now known from Allegheny, Beaver, Cambria, Craw- 

 ford, Erie, Fayette, McKean, and Washington counties. Specimen figured: Meadow Run 

 Valley, four miles south of Ohio Pyle, Fayette Co., Sept. 1-3, 1906. O.E.J. &: G.K.J. 



2. Amblystegium varium (Hedwig) Lindberg 



{Leskea varia Hedwig; Stereodon varius Mitten; Hypniim debile Bridel) 



Plate XLI 



More or less loosely cespitose, green to light-green above, darker below, 

 the stems and branches similar but larger than A. serpens; leaves rather close 

 together, erect- to widely-spreading, the stem-leaves ovate-acuminate, the 

 largest about 1-1.5 mm x 0.5-0.7 mm, usually long-acuminate, somewhat con- 

 cave, the margins entire or very slightly denticulate, plane, the base very 

 slightly decurrent; branch-leaves similar but smaller and more lance-ovate, 

 usually about 0.6-0.8 x 0.3-0.4 mm; costa strong, more or less colored, usually 

 yellowish or brownish, reaching usually into the acumen; medium leaf-cells 

 rhomboid-hexagonal, usually about 2-4:1, somewhat incrassate, rather regularly 

 arranged, the basal larger and more incrassate, sometimes yellowish, short- 

 rectangular, the basal marginal distinctly quadrate; inner perichaetial leaves 

 slenderly lance-triangular, about 1.6 mm long; seta reddish, slender, dextrorse, 

 varying from 1-2 cm in length; capsule reddish-yellow, about 4-6:1, cylindric, 

 arcuate, the urn about 1.3 mm long, rather smooth, even when dry and empty; 

 annulus 2-3-seriate; peristome typically hypnaceous, similar to that of A. ser- 

 pens, the teeth basally confluent, dorsally cross-striolate below, hyaline-papil- 

 lose above, strongly and closely trabeculate; the segments about as long, slightly 

 carinately cleft, the basal membrane about two-fifths as high, the cilia 1 or 2, 

 nodose to shortly appendiculate; lid conic-acute; spores about .012-.018 mm, 

 slightly papillose, medium-walled, mature in late spring: autoicoiis. 



On bases of trees, soil, rocks, rotting wood, etc., in moist woods; Europe, 

 and, in North America, from Canada to the Gulf of Mexico. Very common 

 in our region. Quite variable. 



Now known from Allegheny, Beaver, Butler, Crawford, Erie, Fayette, Lawrence, Mc- 

 Kean, Mercer, Somerset, Washington, and Westmoreland counties. Specimen figured: 

 Slope of Chestnut Ridge above Hillside, Westmoreland Co., September 16-17, 1909. 

 O.E.J, and G.K.J. 



2a. Amblystegium varium var. ovatum Grout 



Slender, more or less julaceous; stem-leaves smaller, 1.2-1.5 mm long, 

 concave, round-ovate, abruptly shortly acuminate; leaf-cells 2:1, the quadrate 



