— 4i — 
2a. Green cells of the branch-leaves in cross section wholly included, (3) el- 
liptic; (4) hyaline cells of the branch-leaves bulging about % their thick- 
ness or less on the inner surface, (5) with 4-8 pores on the outer surface 
and usually 3 on the inner. 
Sphagnum compactum DC. — Alaska to Wash.; eastern N. Amer. 
(PI. XVIII) 
2b. Green cells of the branch-leaves in cross section with widest exposure on 
outer side, or not at all exposed on inner side. 
3a. Green cells of the branch-leaves in cross section triangular. 
4a. Hyaline cells of the branch-leaves bulging about yP their thickness 
or less on the inner surface, (5) with 2-6 pores on the outer surface 
and 4-7 on the inner. 
6a. Branch-leaves undulate toward their tips. 
Sphagnum recurvum Beauv. — Alaska to Wash, and Colo.; eastern 
N. Amer. (PI. XVIII) 
6b. Branch-leaves not undulate. 
Sphagnum recurvum tenue Kling. — Alaska to Wash, and Idaho; 
northern N. Amer. (PI. XVIII) 
4b. Hyaline cells of the branch-leaves bulging about pi their thickness 
or less on the inner surface, (5) with 0-3 pores on the outer surface 
and 0-3 on the inner. 
Sphagnum tenellum Pers. 5 Alaska to B. C.; northeastern N. 
Amer. (PI. XIX). 
2b. Green cells of the branch-leaves in cross section with widest exposure of 
the outer side but also exposed on the inner side. 
3b. Green cells of the branch-leaves in cross section trapezoidal; (4) hyaline 
cells of the branch-leaves bulging % their thickness or less on the 
inner surface, (5) with 5-12 pores on the outer surface and mostly none 
on the inner. 
Sphagnum dusenii Jens. — Alaska. 6 (PI. XIX). 
2b. Green cells of the branch-leaves in cross section with widest exposure on 
the outer side, or equally on the 2 sides. 
3c. Green cells of the branch-leaves in cross section truncately elliptic; (4) 
hyaline cells of the branch-leaves bulging pi their thickness on the 
inner surface, (5) with 10-20 pores on the outer surface and 1-4 on the 
inner. 
Sphagnum subsecundum Nees 7 — Wash, to Mex. ; eastern N. Amer. 
(PI. XIX) 
5 5. molluscum Bruch. 
6 Univ. Calif. Pub. Bot. 2: 313 . 1907 . 
1 S. contorlum Schultz; S. platyphyllum Sull.; 5. rufescens Limpr.r 5. obesunt Wils.; 5. dasy- 
phyllum Warnst.; 5. plicatum Warnst. ; 5. Orlandense Warnst. ; 5. mobilense Warnst.; 5. simile 
Warnst. 
