— 46 — 
2c. Stem-leaves only slightly lacerate at the narrowed tip, or not at all lacer- 
ate; (3) hyaline cells of the branch-leaves bulging pi~}i their thickness 
on the outer side; (4) plants reddish-green or merely green; (5) outer 
surface of the branch-leaves with large elliptic pores. 
Sphagnum robustum (Russ.) Roell. 12 — Alaska to Wash, and Colo.: 
northeastern N. Amer. (PL XXII). 
(1) Cortical cells of the stem, X 125. (2, 3, 4, 5) Stem-leaves, X 22. (6, 7, 8, 9) Hyaline 
cells from the middle regions of leaves of spreading branches, showing pores on outer side, X 343- 
(10, 11, 12, 13) Portions of cross sections of leaves of spreading branches, X 4°o* 
14 5. russowii Warnst. 
