Jennings: Manual of Mosses — 22. Polytrichaceae 159 



Widely distributed, on peaty soil, decayed logs, etc., Europe, Asia, and, 

 in North America, in Canada and northern United States. 



Common in our region and very often found on the cut end of a partially decayed 

 stump or log. Now known from 16 counties in western Pennsylvania and probably occurs 

 m all. Specimen figured: "Rachelwood," New Florence, Westmoreland Co., Sept. 8-11, 

 1907. O.E.J. 



Family 22. Polytrichaceae 



Dioicous, rarely paroicous or synoicous; antheridial flower terminal, large, 

 discoid, generally bearing a shoot in its middle; archegonial flowers terminal, 

 bud-like: perennial, mostly very large, mostly cespitose, with a long horizontal, 

 subterranean, triangular, blackish, branched, radiculose rhizome: stem erect 

 with lower leaves none or remote, leaves weakly costate, three-seriate, without 

 lamellae, red to hyal.'ne, small and scale-like; upper part of stem five-or-more- 

 angled, with specialized central strand; stem structure complex; upper leaves 

 larger, the sheathing base usually yellowish to hyaline, lamina more or less 

 spreading or recurved, when dry mostly erect, sometimes convolute to crispate, 

 mostly lanceolate to lance-subulate, sometimes Ungulate, mostly sharply 

 toothed, mostly plane with erect edges, uni-stratose or with two-stratose zone 

 next the ccsta, rarely two-stratose to the margin, with narrow, vertical, green, 

 longitudinal, m.ostly uni stratose lamellae on the ventral surface of the costa 

 and of the bi-stratose lamina; costa narrow to wide, incomplete to aristate- 

 excurrent, dcrsally often toothed and rarely lamellate, complex in structure; 

 leaf-cells parenchymatous, small, the basal rectangular to linear and narrower 

 towards the margin: seta elongate, mostly solitary, often flattened and weakly 

 sinistrorse; capsule first erect, later inclined to horizontal or pendent, cylindric 

 to prismatically 4-6-sided or cubic, collum various; annulus none or uniseriate 

 with three or four transitional bordering cells; peristome rarely lacking, mostly 

 simple v/ith 32 to 64, rarely 16, lingulate, short, unbarred teeth, triangular in 

 cross-section, rising from a basal membrane, the teeth hyaline, often with a 

 colored median line, incurved to meet the disk-like apex (epiphragm) of the 

 columella; spores mostly small, .00S-.012 or .014-.021 mm, mostly smooth; 

 operculum, apiculate to rostrate from a conic to convex base; calyptra cucullate, 

 rarely glabrous, mostly spinulose to long, villous and felted. 



A cosmopolitan family, mostly on siliceous or other non-calcareous soils: in 

 colder reoioiis often forming laroe masses ur sods. 



N3 



Key to the Genera 



A. Capsules cylindric - B 



A. Capsules four-angled or six-angled 3. Polytrichum 



B. Leaves not crisped when dry; calyptra hairy; protonema persistent 2. Pogonatum 



B. Leaves crisped when dry; calyptra not hairy 1. Atnchum 



1. Atrichum Beauvois 



{Catharinaea Ehrhart ) 

 Stems of moderate height, in loose tufts or gregarious, dark green to bronze 

 when old. central strand generally well developed; rhizome creeping, branched, 

 hearing loosely- to thickly-leaved erect shoots, densely radiculose at the base; 



