114 NORTH AMERICAN FLORA 
Annulus present. 
Cells throughout the lower half of the leaf short, from nearly square to 
mostly 2-4 times as long as wide; capsule not ribbed. 
Cells throughout the lower half of the leaf mostly elongate (except the 
alar), from 2-8 times as long as wide; capsule more or less ribbed 
when dry. ‘ 
Stems usually with flagella 5-6 mm. long in the axils of the upper 
eats : Meee usually 4-5 times as long as wide, mostly erect and 
straight. 
Stems without flagella; capsule usually 3-4 times as long as wide, 
mostly slightly curved and nodding, the mouth slightly oblique. 
Annulus lacking. : 
Leaves with a long-excurrent, terete costa, usually entire; capsule smooth. 
Leaves with the costa vanishing in the slightly broadened, grooved point; 
capsule ribbed. 
10. 
ll. 
12. 
13. 
[VorumeE 15 
. D, fuluum. 
D., flagellare, 
D. montanum, 
D. strictum. 
D. rhabdocarpum. 
3. EvupDICRANUM. Dioicous; male plants either large, in more or less separate tufts, or minute 
and growing on tomentum of the fertile stems; species of medium to large size; stems tomentose; 
costa semiterete, with guide-cells and stereid-bands above and below; capsule curved and nodding 
(rarely nearly straight), often strumose; peristome-teeth vertically striate on the outer plates (smooth 
only in D. laevidens); calyptra smooth. 
Upper leaf-cells short, from mostly square to 2 or rarely 3 times longer than 
broad with cell-walls not pitted. 
Plants robust, with leaves undulate. 
undulate.) 
Setae aggregate. 
Setae solitary. 
Leaves lanceolate below, broadest near the base, mostly nearly 
smooth on the back; lower leaf-cells very narrow, about 8u wide 
with greatly thickened, pitted walls; upper cells with mostly 
equally thickened walls. 
Leaves ovate below, often broadest one third up, mostly papillose 
on the back; lower leaf-cells broader with slightly thickened, 
pitted walls; upper cells with rather unequally thickened walls. 
Medium-sized species with leaves not undulate (or rarely undulate in 
D. condensatum) ; setae solitary. ; 
Upper leaf-cells irregular with somewhat unequally thickened walls; 
leaf widest near the base. 
Upper leaf-cells with uniformly thickened not sinuous walls. 
Leaf with a short, stout point and the costa not excurrent or very 
shortly excurrent. (D. elongatum may be sought here.) 
.Lower leaf-cells broad, 12-16 wide, with scarcely thickened or 
pitted walls; capsule 4-6 times as long as broad. 
Lower leaf-cells narrower, 8-10u wide, with somewhat thick- 
ened, pitted walls; capsule mostly 2.5-3 times as long as 
broad. 
Leaf with a slender point and excurrent costa. 
Leaves serrulate and rough on the back usually one half down; 
alar cells not extending to the costa. 
Leaves entire or slightly serrulate and rough towards the apex; 
leaf point often broken; alar cells extending to the costa. 
Upper leaf-cells elongate with pitted walls (except in D. elongatum, with walls 
--- not pitted and cells often oval or rounded with very thick walls). 
Peristome-teeth smooth on the outer plates. 
Peristome-teeth vertically striate on the outer plates. 
Plants slender: leaves entire or slightly serrulate near the apex, mostly 
3-4.5 mm. long; capsule sometimes nearly straight, about 1.5 
mm. long, with a distinct annulus. 
Leaf-cells with pitted walls not extending to the middle of the leaf; 
' some of the upper cells not elongate. 
Leaf-cells with pitted walls extending to above the middle of the 
leaf; cells all elongate. 
Plants mostly large and stout; leaves serrate above (except sometimes 
in D. neglectum and varieties of D. Bonjeani) and more than 6 
mm. long; capsule 2.5-5 mm. long; annulus wanting (except in 
D, neglectum). 
Setae aggregate. 
Leaves not undulate; costa percurrent or excurrent; tomentum 
not conspicuous on the stems; setae mostly yellow. 
Leaves more or less undulate; costa vanishing in the narrow 
apex. 
renee conspicuously undulate; stems thickened with 
abundant tomentum, grayish above, rusty-brown below; 
seta yellowish; capsule curved and nodding. 
Leaves slightly undulate or not undulate; stems not con- 
spicuously thickened with tomentum. 
Upper stem-leaves up to 13 mm. long; seta dark-red, up 
to 6 em. long; capsule curved, nodding to horizontal. 
(In some of the smaller varieties not 
14. 
15. 
16. 
17. 
18. 
19. 
20. 
21. 
22. 
23. 
24, 
25. 
26. 
27. 
D, Drummondi. 
D. Bergeri. 
D. spurium, 
D. condensatum, 
D, Miihlenbeckii. 
D, brevifolium. — 
D. fuscescens. 
D. fragilifolium, 
D, laevidens. 
Dz, elongaium. | 
D. groenlandicum. 
D. majus. 
D. rugosum. 
D. frigidum, 
