146 A MANUAL OF MOSSES 



erect, red, radiculose at base; leaves erect to erect-spreading, 

 the upper lanceolate to lance-linear, the apex acute and dis- 

 tantly serrulate; costa mostly incomplete; cells lax and thin- 

 walled ; seta elongate, when dry sinistrorse, more or less hooked 

 or curved at the top; capsule more or less pendent, usually 

 short-pyriform, wide-mouthed, almost turbinate, exothecial 

 cells mostly hexagonal and often broader than high; annulus 

 none in our species ; peristomes equal in length ; teeth lanceo- 

 late, finely papillose, not prominently bordered ; inner peristome 

 yellowish, the basal membrane constituting one-half or more 

 of its height ; segments split, cilia 2-3, well developed, weakly 

 articulate ; spores medium size ; operculum medium size, quite 

 convex, often apiculate. 



A genus of about 15 species, distributed over the whole 

 earth, five of these being in North America, one in our range. 



1. Mniobryum wahlenbergii [Weber and Mohr] New 

 Combination. 



(M. albicans Limpricht ; Webera albicans Schimper; Hypnum 

 wahlenbergii Weber an(i Mohr). 



(Plate XVIII) 



Cespitose in soft, large, glaucous or whitish-green tufts: 

 stems usually 2-6 cm. long, more or less chestnut-red, especial- 

 ly in the older portion, slender, flexuous, branched and matted 

 together with a brownish tomentum at base ; leaves remote be- 

 low, in the upper portion rather remote, about 2.5 mm. long, 

 when dry somewhat shrunken but hardly twisted, spreading, 

 widely ovate-lanceolate, at the base narrowed and somewhat 

 decurrent, the margin plane and serrulate towards the obtusely 

 acute apex; costa strong, reddish, ending a little below apex; 

 leaf-cells rhombic-hexagonal, pellucid, about .015-.025 mm. 

 wide, slightly narrower towards margin, tending to become 

 inflated and rectangular at base but hardly distinctly so, the 

 lowermost often reddish : seta erect-flexuous, 2-4 cm. high, 

 slender, yellowish to reddish-brown, abruptly hooked at the 

 summit; capsule pendent, shortly wide-pyriform, about 2.5 

 mm. long, reddish-brown when ripe, the neck short and wide, 

 when dry and empty the capsule wide-mouthed ; annulus none ; 

 peristome-teeth brownish-yellow, pellucid, strongly trabecu- 

 late, the trabeculse often with oblique connections, the lamellae 

 and divisural indistinct, teeth lance-linear, papillose and sub- 

 hyaline at apex; segments equal in length to teeth, narrow, 

 carinately split, the cilia 2-4, sometimes more or less connected 

 al apex, nearly as long as segments, papillose ; basal membrane 

 nearly reaching middle of teeth ; spores smoothish, rather thin- 

 walled, about .018-.024 mm.; operculum convex-apiculate; 

 exothecial cells irregularly quadrate-hexagonal, yellowish- 



