— 44 — 
2a. Stem-leaves rather longer than wide, rather large. 
3a. Stem-leaves with 1 deep rent in the middle at the tip; (4) hyaline cells 
of the branch-leaves with 2-5 small pores on the outer side and 0-10 
lajge ones on the inner. 
Sphagnum riparium Angstr. — Alaska to B. C.; northeastern N. 
Amer. (PI. XX). 
3b. Stem-leaves slightly lacerate at tip, without a rent. 
4a. Hyaline cells of the branch-leaves with 15-20 small pores on the 
outer side and 5-15 small ones on the inner. 
Sphagnum mendocinum Sull. & Lesq. — B. C. to Calif, and Idaho 
(PI. XX). 
3b. Stem-leaves weakly lacerate-fimbriate at tip, without a rent. 
4a. Hyaline cells of the branch-leaves with 3-6 large pores on the outer 
side and 1-4 large ones on the inner. 
5a. Branch-leaves ovate-lanceolate, usually imbricate. 
Sphagnum teres (Schimp.) Angstr. 8 — Alaska to Calif. (PI. XX). 
4b. Hyaline cells of the branch-leaves with 1-10 medium-sized pores on 
the outer side and 0-10 medium-sized ones on the inner. 
5b. Branch-leaves ovate-hastate, usually squarrose. 
Sphagnum squarrosum Crome — Alaska to Calif, and Colo.; 
northeastern N. Amer. (PI. XXI) 
2b. Stem-leaves rather wider than long, rather small, (3) very slightly lacer- 
ate at tip; (4) hyaline cells of the branch-leaves with 7-8 small pores on 
the outer side and 3-4 rather small ones on the inner. 
Sphagnum halticum Russ. 9 — Alaska; Greenland. 
2c. Stem-leaves wider than long, large, (3) widely lacerate at tip; (4) hyaline 
cells of the branch-leaves with 1-4 small pores on the outer side and 1-4 
medium-sized ones on the inner. 
Sphagnum lindbergii Schimp. — Alaska to B. C. ; northeastern N. Amer. 
(PI. XXI). 
Group 4 
la. Outer walls of the surface cells of the stem porose, normally with 1 pore per 
cell. 
2a. Stem-leaves fimbria te-lacerate both at sides and at tip; (3) hyaline cells 
of the branch-leaves bulging pi—pi their thickness on the outer side; (4) 
plant yellowish-green or brownish-green; (5) outer surface of branch- 
leaves with rather small elliptic pores. 
Sphagnum fimbriatum Wils. 10 — Alaska to Calif, and Wyo.; north- 
eastern N. Amer. (PI. XXI). 
2b. Stem-leaves fimbriate-lacerate only across the broad truncate tip; (3) 
hyaline cells of the branch-leaves bulging Yo-} 4 , their thickness on the 
5 5. squarrosulum Sull. 
9 This is not illustrated for lack of material. 
10 5. microphyllum Warnst.; 5. bolanderi Warnst. 
