206 American Midland Naturalist Monograph No. 6 



nodose projections, filiform, etc., sometimes carinate, cilia mostly none; lid 

 convex, obliquely thick-rostrate; calyptra glabrous, cucullate and reaching to 

 base of capsule: spores small. 



A small genus of 4 species; only the following in North America: 



1. Leskeella nervosa [Bridel] Loeske 



{Leskea nervosa Myrin; Lescuraea rigidula Kindberg; 

 Hypnum nervosum C. Mueller) 



Plate XXXIX 



Slender, in thin and appressed tufts, dark green to brownish, the older 

 parts almost black: stems with central strand distinct, creeping, up to 5 or 6 

 cm long, pinnately divided and again branched into numerous, crowded, short 

 and erect or longer and creeping branches, often with numerous gemmiform 

 branches towards the apex; stem-leaves close, broadly ovate, sub-cordate, open- 

 spreading when moist, imbricate when dry, slightly decurrent, about 0.4-0.5 x 

 1-1.2 mm, suddenly long-acuminate, the acumen recurved, the margins plane, 

 sub-sinuate, the blade concave and deeply plicate; costa almost percurrent, 

 slender; branch-leaves considerably narrower, lanceolate, more rigidly erect- 

 spreading, smaller, up to about 0.6-0.7 mm long; leaf-cells oblong to oval- 

 hexagonal, ranging from 1 to 3:1, the alar quadrate to transversely oval-hex- 

 agonal in about 4-6 rows extending well up the margins and becoming rounded; 

 cells smooth to lightly papillose, incrassate; inner perichaetial leaves long- 

 sheathing, long-acuminate: seta 10-12 mm long; capsule erect, sub-cylindric, 

 symmetric, small, castaneous; lid narrowly conic to short-rostrate; peristome 

 short, the teeth whitish, lance-linear; segments shorter, irregular, subulate, 

 basal membrane ^ the length of teeth; cilia none; annulus narrow; spores 

 mature in summer, rough. 



Mostly on bases of trees, especially maples, in our region: Europe, and 

 in the northeastern United States south to Pennsylvania. 



Not common in our region. Crawford Co.: Bark of Black Ash. Conneaut Outlet. 

 C.M.B. Sept. 23, 1949. Fayette Co.: Cheat Haven, September 3-6, 1910. O.E.J, and 

 G.K.J. McKean Co.: Bennett Brook, Bradford, July 12, 1896 (figured), and Bolivar 

 Run, 1896. D.A.B. 



8. Rauia Austin 



Autoicous: quite slender, dull, bluish-green to brownish-green: stems 

 thickly-leaved, simple or divided, more or less regularly pinnately branched; 

 branchlets short, ascending, julaceous, obtuse; leaves dimorphic, drying im- 

 bricate, when moist erect-spreading; stem-leaves plicate, triangular to cordate- 

 ovate, tapering to a lanceolate or lance-subulate acumination, the margins en- 

 tire; costa strong, incomplete; median leaf-cells rounded-angular, with low and 

 usually numerous papillae on both sides; branch-leaves lance-ovate, short- 

 pointed, the costa dorsally somewhat rough; inner perichaetial leaves appressed, 

 pale, lance-oblong, slenderly acuminate, entire, incompletely costate, and with 

 elongate, smooth cells: seta slender, 10-15 mm long, reddish, smooth; capsule 

 from nearly upright to horizontal, oblong-cylindric, mostly weakly curved, 

 light brown, drying more or less constricted below the mouth; annulus revol- 



