Jennings: Manual of Mosses — 31 Hypnaceae 253 



peristome normally hypnoid, teeth msty-yellow, segments broadly split, cilia 2, 

 as long as the segments; spores in summer but capsules very rarely produced. 



One species, as follows, on exposed sunny rocks and ledges, and in dry, 

 grassy places; Europe, Asia, and from Arctic America south through Canada 

 to North Carolina. Usually in hilly or mountainous regions on calcareous 

 substrata. Rare in our region. 



1. Rhytidium rugosum [Ehrhart, Hedwig] Kindberg 

 {Hylocomium rugosum DeNotans; Hypnum rugosum Ehrhart) 



Plate LXVI 



Stems reaching 8 or 10 cm or more, the branches tumid and sometimes 4-6 

 mm in diameter; the leaves 3 mm long or more, sometimes costate above the 

 middle, margins narrowly reflexed. 



Beaver Co.: On ground in Pinus virginiana forest, along Service Creek, one mile 

 west of Raccoon Creek, C. M. Boardman, Feb. 10, 1935 (figured). Huntingdon Co.: 

 T. C. Porter. (Porter's Catalogue). 



16. Hylocomium Bryologia Europaea 



Dioicous, more or less robust, stiffly and laxly cespitose in green or yellow- 

 ish and more or less lustrous tufts: stem mostly very long and procumbent 

 or ascending, more or less arcuate, once to three times pinnate; paraphyllia 

 numerous, much-branched; leaves more or less spreading, concave, mostly pli- 

 cate, oblong to cordate, long-acuminate, plane-margined, serrate; costa thin, 

 double, sometimes reaching mid-leaf; cells linear, mostly smooth, basally shorter 

 and laxer, colored, incrassate, porose, alar not differentiated; inner perichaetial 

 leaves with reflexed-squarrose acuminations: seta more or less elongate, red; 

 capsule inclined to horizontal, thickly ovate or oblong-oval, somewhat dorsally 

 gibbous, with neck short and narrowed into the seta, drying mostly smooth 

 and scarcely constricted below the mouth, annulate; peristome normally hyp- 

 noid; lid convex with a conic-acute point or shortly and obliquely rostrate. 



A small, variously delimited genus mainly inhabiting forests in temperate 

 and cold regions; 3 species in our region. 



Key to the Species 



A. Leaves at base semi-amplexicaul, with very large and rounded auricles; stems erect 



or arched 3. H. brevirostre 



A. Leaves with broad insertion but not with rounded auricles B 



B. Stem closely 2-3 pinnate; leaves obscurely bi-costate, rarely reaching midleaf 



1. H. splendens 



E. Stem irregularly or distantly 1-2 pinnate; costa double and reaching to mid-leaf 



or more 2. H. umbratum 



1. Hylocomium splendens (Hedwig) Bryologia Europaea 



{Hypnum splendens Hedwig; Hylocomium proliferum Lindberg ) 



Plate XLVII 



Widely cespitose in loose mats, lustrous, yellowish to brownish or olive- 

 green: stems long, trailing, red, with green, branched paraphyllia, stems some- 



