24 American Midland Naturalist Monograph No. 6 



1-1.5 cm long, from a turgid 3 mm-thiclc portion (wet) rather suddenly taper- 

 ing to a thin point; branch leaves 2-2.5 mm long, broadly ovoid, cucullate, at 

 the margin with a border of about 2 rows of liner cells, of which a few project 

 outwards as minute teeth, the cucullate apex minutely dorsally scabrous by 

 erosion of the cell walls; median hyaline cells of branch-leaves about 3-4:1, 

 strongly fibrillose, somewhat pcrose dorsally, ventrally more so with distinct 

 pores, the chlorophyllose cells ovoid to triangular-ovoid with the ventral end 

 flush with the hyaline cells but dorsally being much exceeded by the convex 

 hyaline cells. 



On the sides of the chlorophyllose cell-walls facing the hyaline cells there 

 are minute papillae in many of the leaves, but apparently not all. These 

 papillae seem best developed in the basal half of the leaf. 



Crawford Co.: Pymatuning Swamp, Linesville. O.E.J. May 26-27, 1934 (Det., 

 C.M.B. ). McKean Co.: Cathrine Swamp, on plateau, elevation 2080 ft. C.M.B., Sept. 

 2, 1948 (figured). Somerset Co.: Glade Run bog, Negro Mt. Elev. 2470 ft. C.M.B., 

 July 15, 1949. 



3. Sphagnum affine Renauld and Cardot 



{S. imbricatum var. affine Warnstorf) 

 Plate I 



Densely cespitose, usually bluish or glaucous-green above and more or less 

 yellowish below: stems robust, sometimes as much as a decimeter in length, 

 usually much less, densely branched; cuticular sheath distinct, three-layered, 

 the inner layer with the largest cells, the outer cells usually densely spirallv 

 fibrillose and 2-6-pored; stem-leaves large, 1.6-2.2 mm long, about two-thirds 

 as wide, widely spatulate, the rounded upper half somewhat concave, erose- 

 fimbriate; hyaline cells of stem-leaves usually weakly fibrillose in their upper 

 half, porose dorsally, the hyaline cells below non-fibrillose, the pores large and 

 few; branches usually 4, one or two of these very slender, pendent and rather 

 closely appressed to the stem, the divergent ones horizontally spreading, with 

 drooping tips, rather swollen below, tapering towards the apex, the branches 

 often 2 cm long; branch-leaves 2-3 mm long, broadly ovate, bluntly and cucul- 

 lately short-pointed, the whole leaf very concave and with more or less in- 

 volute margins, the apex dorsally scabrous by the erosion of the outer cell- 

 walls; hyaline cells of the branch-leaves rather wide, spirally fibrillose on both 

 sides, with large well-defined pores of one-third to one-half the cell-width and 

 confined mainly to the cell-angles; chlorophyllose cells in cross-section widely 

 trapezoidal, the wider face being ventrally exposed and more than or at least 

 half of the width (dorsal- ventral) of the smooth lateral walls, the dorsal face 

 exposed and rather narrow*; the cuticular cells of the branches porose and 

 densely fibrillose: fruit not seen. 



In bcygs and swampy borders of ponds and streams. Europe and in North 

 America from Canada to Florida. Common in the more northern counties in 



* The chlorophyllose cells are more nearly equilaterally triangular th.m appears in our 

 drawing in Plate I. 



