OF WESTERN- PENNSYLVANIA. 31 



truncate, erose-dentate, the margins rather widely hyaline- 

 hordered ; hyaline cells of stem-leaves broadly rhomboidal, 

 non-porose, non-fibrillose ; branches short, usually not over 1 

 cm. long, 3 or 4 to a fascicle, one or two thick, horizontally 

 spreading or somewhat upcurved, the others slender and ap- 

 pressed-pendent ; branch-leaves when dry with the upper half 

 of the leaf more or less squarrose-spreading, large, 2-3 mm. 

 long, ovate, concave, the margins narrowly bordered, the upper 

 margins involute and often slightly erose-ciliate or erose-den- 

 tate, the apex erose-dentate and cucullate ; hyaline cells of 

 branch-leaves rather broadly rhomboidal, fibrillose, dorsally 

 with several large, round pores irregularly scattered and also 

 in the cell-angles, the pores about two-fifths as wide as the 

 cell, sometimes a few oval and lateral, ventrally the pores 

 small, oval, and located in the cell-angles ; in cross-section the 

 chlorophyllose cells are elliptic, enclosed both dorsally and ven- 

 1 rally by the moderately convex hyaline cells; cuticvilar cells 

 of the branches large, short-rectangular, with one large apical 

 pore: fruit not seen. 



In bogs and wet woods, widely distributed in the North- 

 ern Hemisphere, in North America occurring from the Arctic 

 regions south to the northern part of the United States. Rare 

 ill our region. 



Center: Margin of bog under Pinus rigida, "Barrens," near 

 Scotia, September 22, 1909. O. E. J. (Figured). 



6. Sphagnum squarrosum [Persoon] Schwaegrichen. 

 (S. teres var. squarrosum Warnstorf ; 5. crassisetum Bridel). 

 Loosely cespitose, bluish- to yellow-green: stems long, 

 loosely branched, with wood-cylinder hyaline to greenish or 

 yellowish, cuticular sheath distinctly 2-3-layered; stem-leaves 

 broadly oblong-lingulate, the apex broadly rounded and erose- 

 fimbriate, the leaves very narrowly bordered, slightly auricu- 

 late, non-fibrillose, the hyaline cells above short and broad; 

 branches 4 or 5, two or three tumid, horizontal, the leaves on 

 the lower two-thirds of the divergent branches with squarrose 

 tips ; branch-leaves ovate-lanceolate, very concave, the apex 

 acuminate with involute margins, margins narrowly hyaline- 

 bordered ; hyaline cells of branch-leaves richly fibrillose, on 

 both sides with numerous large round pores of about one-half 

 the width of the cell; in cross-section the chlorophyllose cells 

 free on both surfaces, narrowly rectangular to trapezoidal, 

 when trapezoidal with the wider face dorsal, the faces thick- 

 walled, the lumen more or less elliptic, the hyaline cells strong- 

 ly dorsally convex: spores yellowish and finely roughened, 

 about .022 — .025 mm. in diameter. 



In usually shaded locations in swamps, boggy springs, 

 along woodland streams, etc., in Europe, and, in North 



