40 A MAXUAL OF AtOSSES 



tinct two-layered sheath of inflated cells; stem-leaves small, 

 about 1 mm. long, broadly lingulate or triangular-lingulate, 

 the hyaline border much broader towards the base, the apex 

 broadly rounded and more or less concave, cucullate, and 

 erose-fimbriate ; hyaline cells of stem-leaves in upper third 

 fibrillose, short and broad, ventrally with a few cells in the 

 angles, dorsally with more numerous small ringed pores along 

 the sides of the cell, very few of the hyaline cells septate, the 

 lower ones long and narrow ; fasciculate branches 3-5 to a 

 fascicle, usually two slender and closely appressed pendent, 

 two divergent and recurved; branch-leaves about 1.5-2 mm. 

 long, broadly ovate to lanceolate, more or less sharply acumi- 

 nate, the upper margin involute and narrowly hyaline-bord- 

 ered, leaves when dry more or less subsecund and sublustrous ; 

 hyaline cells richly fibrillose, slender, ventrally almost pore- 

 less, dorsally with small ringed pores more or less completely 

 arranged in bead-like rows, the pores most numerous towards 

 upper margins of leaf ; in cross-section the chlorophyllose cells 

 narrowly barrel-shaped, with both faces free and their walls 

 there somewhat thickened ; cuticular cells of branches apically 

 porose : spores not seen but reported as .020-.030 mm. in 

 diameter, yellowish-brown, finely roughened. 



In swampy meadows, along ditches, margins of bogs, etc., 

 in Europe and, in North America (from New England to 

 Eastern Pennsylvania and Ohio. Not heretofore reported from 

 our region but a specimen collected by J. A. Shafer, October 

 20, 1901, at Ohio Pyle, Fayette County, is evidently very close- 

 ly related to this species, differing, however, in having the 

 stem-leaves about .7-.8 mm. long, with the margin uniformly 

 narrowly hyaline-bordered and the hyaline cells fibrillose to 

 below the middle of the leaf. 



16. Sphagnum platyphyllum (Sullivant) \Yarnstorf. 

 (S. auriculatuni Aongstroem; S. isophyllum Russow). 



(Plate IV) 



Loosely cespitose. brownish- to grayish-green : stems in 

 our region up to 10 cm. high, slender, rather weak and sparse- 

 ly branched; stem in cross-section showing a usually brown- 

 ish \vood-cylinder, with a distinct cuticular sheath of rather 

 small, thin-walled, and usually uni-porose cells; stem-leaves 

 large, usually 1.3-2.0 mm. long, oval to oblong from an 

 auriculate base, very concave, the apex blunt and a little 

 toothed or erose, the margin narrowly and uniformly bordered ; 

 hyaline cells of the stem-leaves in lower half to two-thirds of 

 the leaf non-fibrillose and non-porose but some of them sep- 

 tate, in the upper half or one-third of the leaf the hyaline cells 

 fibrillose and on both sides with lateral rows of small pores-; 



