THE POLYTRICHACEZ OF WESTERN NORTH AMERICA 307 
thick; lamina smooth at back. Margin plane or broadly incurved, 
not bordered, usually with large teeth. Lamellz on upper side only, 
very numerous, erect, high, not wavy from side to side, entire or 
nearly so. Vein often toothed at back near apex. Cells of sheath 
without chlorophyll, elongated-rectangular to linear, toward the 
edge longer than along the vein; cells of lamina small, thick 
walled, quadratic or hexagonal, at base often broader than long, 
often in rows at the margin. 
Calyptra matted with very long white to brown hairs which cover 
the whole capsule. 
Capsule erect when young, later inclined, finally often horizon- 
tal, 4-6 angled or terete, cubical to oblong; hypophysis hemispheric 
and grading into capsule, or discoid and deeply constricted from 
capsule, with large 1-celled stomates. Peristome present; teeth 64. 
Lid large, plane to conic, beaked. Pedicels single, long, rigid, yel- 
lowish-red to purple, twisted to the right above when dry. 
Number of species in western North America, 12; total number 
species, about 104. 
THE WEST NORTH AMERICAN SPECIES,—-A COMPARISON AND KEY. 
1. Leaf margin serrate to sheath or nearly so. 
2. Margin plane or erect. | 
3. Leaves sharply pointed, the point composed mostly of the ex- 
current vein. 
4. Leaf point red, dentate, about 1 mm. long. 
5. Marginal cells of lamelle like the rest, sometimes slightly 
flattened or elongated, not thickened, width to height 
about as 1:1. 
6. Capsule about as 1:14, obscurely 5-6 angled. 
7. Plants 23-10 cm. long. 
a. Cells near middle of sheath and 3 distance from 
margin to vein about 3-4 times as long as wide; 
leaf blade about middle 1 cell thick for 4-8 cells 
(TOME MIATCIM Mee eke he aie us tT. 2 cracile: 
6. Capsule about as 1:17, sharply 4-6 angled. 
7. Plants 7-20 cm. high. 
a. Cells near middle of sheath and # distance from 
margin to vein about 6-10 times as long as wide; 
leaf blade about middle 1 cell thick for 2-3 cells 
PEO IMD MATS sical eee thee 2. P.attenuatum. 
5. Marginal cells of lamellee oval or flattened, thickened, width 
to height about as 13—2:1. 
6. Capsule about as 1: 2-24, sharply 4-6 angled. 
Wi tel MONUS Chay CaN ana ge Gye Ge ede c.8 3. P. ohioense. 
