30 American Midland Naturalist Monograph No. 6 



sheath usually three-layered, the outer cells perhaps a little the largest, non- 

 fibrillose, usually not distinctly porose, the wood-cylinder strong, yellowish or 

 rarely castaneous; stem-leaves large, about 1.5 mm long, broadly triangular- 

 lingulate, the margin narrowly hyaline-bordered, the rounded to somewhat 

 truncate apex erose-dentate, the base often slightly auriculate; hyaline cells of 

 stem-leaves non-fibrillose, non-f)orose, in the lateral portions of the basal half 

 of the leaf often septate, the upper hyaline cells about as broad as long; 

 branchs 3 to 5 to a fascicle, usually two appressed- pendent and very slender, the 

 others widely divergent but somewhat recurved, rather slender, about 1-1.5 cm 

 long; branch-leaves when dry imbricate but with the apical half of some of 

 them squarrose, the leaves usually 1.5 mm long, ovate, concave, the narrowly 

 hyaline-bordered margin involute towards the apex; hyaline cells of branch- 

 leaves short, wide, both ventrally and dorsally fibrillose, and with a few large 

 round pores about half as wide as the cell and usually located in the cell- 

 angles; in cross-section the chlorophyllose cells in the apical third of the leaf 

 trapezoidal to barrel-shaped and exposed both dorsally and ventrally, wider on 

 the dorsal face, towards the base of the leaf sometimes triangular and exposed 

 only dorsally; cuticular cells of branches rectangular: spores not seen but said 

 to be brownish, papillose, and about .025 mm in diameter. 



In bogs, wooded swamps, etc., in Europe and, in North America, in Can- 

 ada and the northern United States, probably distributed widely with the 

 type form. 



Crawford Co.: In tamarack bog one and one-half miles s.e. of Linesville, June 7, 

 1904 (figured) and June 12, 1905. O.E. This station is now submerged. Erie Co.: In 

 swamp near south shore of Presque Isle, August 3, 1935. Nelle Ammons. Somerset 

 Co.: Millers Run. O.E.J. 



Subsection IV. Cuspidata 



Chlorophyllose cells of branch-leaves triangular to trapezoidal, exposed on 

 the dorsal (outer) surface, sometimes narrowly on the ventral surface. 



10. Sphagnum recurvum Beauvois 



(S. intermedium Hoffman; S. apiculatum Lindberg) 

 Plate III 



Loosely but deeply tufted, pale green to greenish- or whitish-yellow: stem 

 light green, slender, long, in our region often up to 3 dm long, the cuticular 

 sheath rather indistinct and consisting of 3 or 4 layers of small or medium- 

 sized rather thick-walled cells; stem-leaves small, about 0.5-0 8 (-1.0) mm long, 

 equilaterally triangular to ovate-triangular, obtuse and slightly erose- denticu- 

 late; hyaline cells of stem-leaves rather small, mostly non-fibrillose and non- 

 porose, towards the base on each side of the leaf more or less septate and nar- 

 rowing to form a very wide border, which abruptly narrows above but reaches 

 almost to the apex; branches usually 4, two very slender and appressed-pendent, 

 two somewhat larger and irregularly spreading; cuticular cells of the branches 

 elongate-rectangular, perforate and somewhat recurved at the apex, like those 

 of the stem non-fibrillose; branch-leaves lance-ovate, imbricate, in our region 



