258 BULLETIN OF THE UNIVERSITY OP WISCONSIN. 



involute; hyaline cells abundantly fibrillose, not divided or somewhat 

 divided towards margins, inner surface with small pores in almost all cell 

 angles particularly in upper half, outer surface with pores in rows along 

 commissures, less numerous towards base. Hedwigia 31: 180. 1892. — Mo- 

 bile, Alabama. 



23. Sphagnum simile Warnst. — Stem leaves small. Ungulate; hyaUne 

 cells at apex only occasionally divided by a cross wall, hyaline border of 

 apex partly resorbed and- fimbriate, upper part of leaf fibrillose; branch 

 leaves oval to oblong-ovate, both sides abundantly porose, inner surface 



with small pores in almost all cell angles, outer surface with pores along 

 commissures; chlorophyll cells in cross section parallel-trapezoidal and free 

 on both faces. Hedwigia 33: 326. 1894. — Madison, Wisconsin. 



23a. Sphagnum TVaghornei Warnst. — Chlorophyll cells of the branch 

 leaves in cross section broadly isosceles-trapezoidal, the longer side on the 

 inner face, exposed on both faces, walls uniformly thickened; hyaline cells 

 smooth within where they adjoin green cells: wood body dark brown to 

 almost black: cortical cells with spiral fibrils and outer wall with 1 (rarely 

 2) large pores: otherwise as in all Ctjibii'olia. Hedwigia 33: 329. 1894. 

 — Newfoundland. 



24. Sphagnum rufescens Bryol. Germ. — Seldom completely submersed: 

 stem leaves large, triangulax-linguiform, lateral margins narrowly and uni- 

 formly bordered down to base; hyaUne cells fibrillose from apex far down- 

 ward, often quite to base, and with small pores on both sides, on inner 

 side especially in cell angles, on outer side mostly in interrupted rows on 

 commissures: branch leaves large to very large, ovate-lanceolate with nu- 

 merous small pores on inner side, sometimes in rows near margins, still more 

 numerous on outer side, in rows, like strings of pearls, on commissures; 

 rings strong. Bot. Gaz. 15: 246. 1890. Hedwigia 33: 326. 1894.— Prom 

 Newfoundland, Labrador and Canada to Connecticut; also Washington 

 and California. 



24:0. Sphagnum medium Limpr. — Stem leaves as in S. cymhifolium, 

 larger, plicate, rarely in upper half with a few fibrils and few large pores; 

 branch leaves involute all around, pores more numerous on the outer sur- 

 face, especially in cell angles: dioicous. Laubm. 1: 104. 1890. — From New- 

 foundland and Labrador through Canada to Florida. 



25. Sphagnum Ludovicianum (Een. & Card.) Warnst. — Stem leaves 

 very large, broad-lingulate, apex cucullate and the margins there invo- 

 lute, narrowly bordered all around; fibrillose to base, inner surface with 

 pseudo-pores where three cell angles meet, near margin with large or small 

 pores, outer surface with narrow elliptic pores along commissures, larger 

 below; or stem leaves narrow at base and broadened to middle, then nar- 

 rowed into a broad rounded cucullate apex with involute margins: fasci- 

 cles 3-4-l»anched 2 spreading: branch leaves large, ovate, apex hyaline 



