— 3 — 
Leaves lanceolate, about 2.4 mm. long, loosely appressed when dry, recurved 
when moist, nearly all hyaline pointed; surfaces nearly smooth; margin 1 cell 
thick throughout. Cells of leaf-tip isodiametric, of leaf-middle rectangular, 
of leaf-base linear. Dioicous. Calyptra somewhat rough on the beak. Seta 
5-8 mm. long, twisted to the right. Capsule erect, cylindric or almost club- 
shaped, its body 2-2.4 mm. long; lid half as long as capsule-body, its beak straight; 
annulus of 2-3 rows of cells. Peristome-teeth .25-45 mm. long, densely papil- 
lose, split to the -base into 2 divisions. Spores 14-18/4 in diameter. — Alaska 
and Yukon to Oregon and Colorado. 
R. heterostichum together with R. sudeticum, R. affine and R. macounii con- 
stitute a very closely related group. It is doubtful whether the last 3 named 
are sufficiently distinct from R. heterostichum to merit specific rank. All differ 
from R. heterostichum in having the margin in the upper part of the leaf more 
than 1 cell thick. 
6. Rhacomitrtum sudeticum (Funk) B. S. G. Bryol. Eur., fasc. 25-28. 1845. 
Plants green to blackish-green. Stems up to 15 cm. long; elongated branches 
few, short tuft-like lateral branches none to few. Leaves lanceolate, almost 
smooth, mostly with short denticulate hyaline points with or without surface 
denticulations; margin 2 cells thick at least in the upper part of the leaf. Cells 
of the leaf-tip round-quadrate, those below the leaf-middle gradually longer, 
of the leaf-base linear; marginal row at base quadratic to rectangular, almost 
hyaline. Dioicous. Seta 2-3 mm. long, twisted to the right. Capsule erect, 
oval, smooth, its body 1.2-1.5 mm. long; lid about % the length of the capsule- 
body, straight-beaked. Peristome-teeth about .4 mm. long, densely papillose. 
Spores 10-18/4 in diameter. 
Macoun’s numbers 156 from McLeod Lake, and 404 and 405 from Rogers 
Pass, distributed as R. affine , are referred here. 
Typical. 
1. None of the leaves with denticulations on the surface of the hyaline points. 
■ — Alaska and Yukon to Oregon and Idaho. 
6a. Rhacomitrium sudeCcum occidentale (R. & C.) n. comb. [R. hetero- 
stichum occidentale R. & C. Bot. Gaz. 15: 41, 1890; R. occidentale R. & C.; 
R. hrevipes Kindb.; R. micropus Kindb.] 
1. At least some of the leaves with denticulations on the surface of the hya- 
line points. — British Columbia to Oregon. 
The surface denticulations seem to constitute about the only distinction 
that one can depend upon to separate the variety, and even that leaves one in 
doubt at times. The leaf-margin is 2 cells thick toward the tip. This removes 
it from R. heterostichum and allies it with the other members of this complex. 
It lacks the short tuft-like lateral branches of R. affine , and its leaf-tips are much 
more like those of R. sudeticum than like those of R. macounii. It is therefore 
placed as a variety of R. sudeticum. It might be recognized as a species; but 
the writer is inclined to believe that it, R. sudeticum, R. affine, and R. macounii 
are all largely if not entirely environmental forms of the same thing. 
