Jennings: Manual of Mosses — 31. Hypnaceae 263 



pellucid, porose, the alar portion with several oblong inflated hyaline cells, 

 above which is a patch of about 9-15 smaller, incrassate, quadrate to oblong- 

 hexagonal cells often more or less castaneous-pellucid: seta 1.5-2.0 cm long, 

 de.xtrorse, castaneous, lustrous; capsule about 1.8 mm long, oblong, inclined 

 to horizontal, arcuate, bright castaneous with a darker and lustrous rim, when 

 dry narrowed below the mouth and sub-costate or smooth; lid short, conic- 

 acute; peristome-teeth lance-subulate, brownish-pellucid, more or less narrowly 

 hyaline-marained, dorsally cross-striolate below, the divisural line and the 

 lamellae fairly distinct, above hyaline and papillose, the trabeculae numerous 

 and strong; segments pale, about as long as the teeth, carinately split between 

 the articulations, the basal membrane about two-fifths as high, the cilia usually 

 2, hyaline, nodose, somewhat shorter than the segments; exothecial cells rather 

 thin-walled, quadrate-hexagonal to oblong-hexagonal, at the mouth smaller 

 and deeply castaneous; spores medium-walled, somewhat brownish, smooth or 

 very nearly so, about .015-.018 mm, m.-^.ture in summer. 



On decaying logs in moist and cool places, usually in hilly or mountainous 

 regions; Europe, Asia, .='.nd, in North America, from New Brunswick to 

 British Columbia and southwards to the northern United States. 



Armstrong Co.: West bank Allegheny River, Foxburg. June 10, 1934. C.M.B. 

 Fayette Co.: Laurel Run, 2 mi. e. of Wymp's Gap, elev. 2100 ft. Aug. 24, 1940. 

 C.M.B. McKean Co.: Leer's Run on decaying log, August 5, 1895 (figured). Lang- 

 made Hollow, August 11, 1895. Gates' Hollow, October 27, 1895, and Bennett Brook, 

 August 8, 1897. D.A.B. Somerset Co.: Cranberry Glade Run, Laurel Hill. On log 

 in swampy woods. June 22, 1947. C.M.B. 



4. Stereodon imponens (Hedwig) Lindberg 



(Hypnum imponens Hedwig; H. cupressiforme Hooker) 



Log Moss 



Plate XLIX 

 Robust in flat, thin, widely interwoven tufts of a yellow-green color: stems 

 rigid, reddish-brown, with numerous paraphyllia, closely, rather regularly and 

 more or less complanately pinnate, prostrate or sub-erect, sometimes reaching 

 more than 10 cm in length; stem-leaves usually somewhat complanate-secund. 

 from a triangular-oblong base gradually long-acuminate, the base not e.xcavate, 

 scarcely decurrent, the acumen strongly falcate-secund, the whole leaf about 



2 x 0.5-0.7 mm, serrulate above, the margin often narrowly recurved below; 

 branch-leaves narrower, otherwise similar to the stem-leaves, about as long; 

 costa short and double or none; median leaf-cells linear- vermicular, about 10- 

 15:1, the basal broader and more or less orange-pellucid, the alar cells sub- 

 quadrate, a few somewhat inflated at the extreme angles, forming a small but 

 quite distinct auricular patch of an orange-brown color, all cells rather incras- 

 sate; perichaetial leaves plicate, ecostate, spinose-serrulate above: seta about 



3 cm long, castaneous, sinistrorse when dry; capsule cylindric, nearly erect, 

 slightly curved, about 3-4 mm long, castaneous, about 4-6:1; lid convex at 

 base with an oblique long-acuminate point; peristome normally hvpnoid, the 

 teeth strongly trabeculate, the trabeculae often dividing, the lamellae and 



