470 Best: REVISION OF THE 
L. gracilescens is quite common and widely distributed, rang- 
ing through the Eastern, Middle, Northern and Western States, 
rare in Canada and in the Southern States and absent west of the 
Rocky Mountains. It differs from the closely related L. polycarpa 
by its smaller straight leaves which are shorter and comparatively 
broader, usually gradually acute and blunt-pointed, and by its 
shorter, often unequal segments. In some of its forms it ap7 
proaches L. polycarpa, in others L. obscura, without however fitting 
either as a variety. In general terms it may be said that all those 
doubtful forms that plainly do not belong to either of these species 
should be referred to L. gracilescens, which moreover has priority 
over the last. 
6. Leskea opscuraA Hedw. Spec. Musc. 223. fl. 57. f. I-9: 
1801. 
Leskea obtusa Ren. & Card. Bot. Gaz. 17: 296. 1892. 
Leskea? Cardoti Kindb. Rev. Bryol. 22: 83. 1895. 
In loose, spreading tufts, rarely in mats, deep green to dark 
olive green, older parts rusty brown; stems prostrate, 3-5 cm. 
long, radiculose, sparingly branched ; central strand small, dis- 
tinct: paraphyllia few, lanceolate, or none: branches short, tumid, 
or elongated and slender: stem-leaves incurved-appressed when 
dry, patulous when moist, oblong-ovate, 0.4-0.6 mm. wide, 
0.8-1.3 mm. long, straight or slightly curved, thickish, concave, 
subcarinate, asymmetric, margins plane, apex rounded-obtuse of 
subacute, entire or serrulate, costa disappearing below apex ; 
branch-leaves similar, more symmetric, obtuse, acute or short 
acuminate ; leaf-cells somewhat uniform, pluripapillate on lower 
surface with small papillae, papillose or nearly smooth on upper ; 
median cells quadrate-hexagonal, 8-10» wide; basal quadrate- 
oblong; apical smaller and roundish: monoicous: perichetial 
bracts erect, appressed, inner subvaginant, costate, blunt-pointed ; 
pedicel smooth, reddish, 1-1.5 cm. long ; capsule erect, straight, 
oblong-cylindric, thin-walled, yellowish, wrinkled and_ slightly 
contracted below mouth when dry; urn 1.75-2.25 mm. long, 
0.8 mm. wide ; exothecial cells oblong-rectangular ; teeth linear- 
lanceolate, yellowish, papillose, lamellate, divisural line distinct 
below, faint above; endostomial band yellowish, about one fifth 
the length of the teeth ; segments linear, densely papillose, more 
“*L. obscura ?’’ In this connection it is worthy of note that Hedwig did not regard 
any of the Muhlenberg mosses as Z. folycarpa, with which, it is to be presumed, he 
was familiar. : 
