OF WESTERN PENNSYLVANIA 211 



1. Climacium dendroides [Linnaeus] Weber and Mohr. 



(Hypnwni dcndroidcs Linmeus; Lcskca dendroides Hedwig). 



Dendroidal, robust, bright or yellowish-green ; the prim- 

 ary stems underground, creeping, divided ; the secondary stems 

 rising to a height of sometimes 10 cm., leafless below, bearing 

 at the summit numerous erect-spreading, rlexuous, usually 

 straight branches ; leaves large ; stem-leaves broadly amplex- 

 icaul, with a more or less rounded and cucullate or apiculate 

 apex; branch-leaves imbricated, giving to the branches a thick 

 -and turgid appearance, about 2x0.7 mm., lance-oblong to lingu- 

 late-oblong, denticulate at base but quite sharply serrate above, 

 plicate, somewhat cordate at the base ; costa nearly reaching 

 apex; median leaf-cells about 6-10:1, linear-rhomboidal to 

 linear-hexagonal, shorter and wider towards the apex and to- 

 wards the base, the alar somewhat lax, wider, hyaline, few, 

 forming small auricles ; perichaetial leaves entire, non-plicate, 

 the inner sheathing: seta deep red. about 2.5-3 cm. long; 

 capsule erect, castaneous, oblong-cylindric, about 4 mm. long, 

 about 3-4:1: lid often remaining attached to the columella, 

 straight, acutely rostrate ; calyptra reaching to below the cap- 

 sule ; peristome large, the teeth forming a cone when moist 

 but usually curved in between the segments when dry; spores 

 mature in fall, green in color. 



On wet ground in marshes, at borders of streams, mar- 

 gins of swamps and lakes, etc. ; Europe, Asia, and from Arctic 

 America south to New Jersey. It may eventually be found 

 to occur in the northern part of our region. 



2. Climacium americanum Bridel. 

 (Plate XXXI) 



Loosely cespitose, robust, yellowish-green, lustrous: prim- 

 ary stems creeping stolon-like in the leaf-mould, throwing up 

 at intervals dendroidal secondary stems to a height of 5-8 

 cm. ; secondary stems with large, scattering to closely im- 

 bricate, ovate, scale-like leaves below, above bearing a closely 

 tufted group of branches ; branches ascending, 1.5-2.5 cm. long, 

 terete, acute to obtuse: branch-leaves 1.7-2.2 mm. long, about 

 two-fifths as wide, broadly lanceolate, sharply serrate in upper 

 half, often denticulate below, acute, broadly auriculate, erect- 

 spreading, when dry imbricate, strongly bi-sulcate : costa 

 strong, ending just below apex; median leaf-cells oblong-hexa- 

 gonal with more or less rounded or truncate ends, 5-7:1, rather 

 incrassate. those of the auricles quadrate along the margin to 

 diamond-shaped towards the interior, the apical and the upper 

 marginal larger and rhombic-oblong: seta erect, stout, dex- 

 trorse above, sinistrorse below, castaneous. about 1-1.6 cm. 

 long; capsule castaneous, narrowly cylindric. about 3-5 mm. 



