Parr 2, 1913] DICRANACEAE 87 
those toward the base wider; perichaetial leaves up to 3 mm. lon from an ovate-lanceolate, 
clasping base more abruptly narrowed to a spreading-flexuous grooved limb with the leaf- 
margin often distinctly crenulate at the shoulder: seta slender, reddish, up to 18 mm. long: 
capsule rather pale and thin-walled, obovate, when dry and empty wide-mouthed, deeply 
furrowed and obcuneate, about 0.75 mm. long with a conic-rostrate lid of about the same 
‘length; exothecal cells mostly elongate, with slightly thickened somewhat sinuous walls; 
annulus large, often nearly simple; peristome-teeth up to 80 wide and 3504 high, divided 
nearly one half down into slender 
TYPE Locality: Sweden. 
DIsTRIBUTION: Arctic America to Montana and Idaho; also in Europe and Asia. 
ILLustRations: Hedw. Descr. 2: pl. 33;B.S. G. Bryol. Eur. pl. 504; Rab. Krypt.-Fl. 4: f. 115. 
Exsicc.: Drummond, Musci Am. 101; Macoun, Can. Musci 504. 
This species usually seems to be dioicous, but sometimes fertile plants bear a short branch 
under the perichaetium with an inconspicuous male flower. 
12. Dicranella secunda (Sw.) Lindb. Musci Scand. 26. 1879. 
Dicranum secundum Sw. Sv. Vet.-Akad. Nya Handl. 16: 244. 1795. 
Dicranum subulatum Hedw. Sp. Musc. 128. 1801. 
Dicranum curvatum Hedw. Sp. Muse. 132. 1801. 
Dicranella curvata Schimp. Coroll. Bryol. Eur. 13. 1855. 
Plants in soft green tufts; stems up to 2 cm. high, with leaves more or less erect or spread- 
ing-flexuous, often curved-secund: upper stem-leaves from an ovate-lanceolate base rather 
gradually narrowed to a slender, grooved subula, denticulate to nearly entire at the apex; 
costa 40-45 u wide at the base, about one fifth of the width of the leaf-base, more or less excur- 
rent, the narrow leaf-blade becoming indistinct or wanting some distance below the apex; 
upper leaf-cells very narrow, 3-4 u wide and up to 40 » long, the basal ones about as long and 
twice as wide; perichaetial leaves denticulate at the apex and more or less crenulate-denticulate 
at the shoulder, up to about 3 mm. long, the inner one or two convolute often one half up, 
abruptly, sometimes almost truncately narrowed to an erect subula, usually shorter than the 
next outer leaves, which are less clasping, with shorter ovate or obovate base only about one 
fourth the subula in length: seta erect, red, 10-16 mm. long: capsule short-oblong, more or 
less curved and nodding to horizontal, not strumose, ribbed when dry, with broad annulus 
and long, obliquely rostrate lid; exothecal cells mostly irregularly elongate with somewhat 
sinuous, thickened walls; peristome-teeth 50-60 » wide and 350 u high, reddish-brown, divided 
scarcely one half down, striate below, with the inner lamellae often distant, and the basal 
membrane usually not evident above the mouth and 3 or 4 rows high of narrow, rather indis- 
tinct cells: spores slightly papillose, up to 18 » in diameter. 
TYPE LOCALITY: Sweden. 
DIsTRIBUTION: From subarctic America to the White Mountains in the East and to California 
in the West; also in Europe and Asia. 
ILLUSTRATIONS: Hedw. Sp. Muse. #l. 31, 34; B.S.G. Bryol. Eur. pl. 60, 61. 
Exsice.: Drummond, Musci Am. 98; Sull. & Lesq. Musci Bor. Am. 50; ed. 2. 66; Aust. Musci 
App. 469; Macoun, Can. Musci 28; Holz. Musci Acroc. Bor. Am. 305. 
13. Dicranella pusilla (Hedw.) E. G. Britton. 
Dicranum pusillum Hedw. Descr. 2: 80. 1789. 
Dicranum cerviculatum Hedw. Descr. 3:69. 1791. 
Dicranella cerviculata Schimp. Coroll. Bryol. Eur. 13. 1855. 
Dicranella polaris Kindb. Ottawa Nat. 5: 195. 1892. 
Plants in rather compact, green or yellowish-green mats, with simple stems rarely more than 
lcm. high: stem-leaves erect-spreading, flexuous, sometimes curved-secund, from an ovate to 
ovate-lanceolate, scarcely clasping base, gradually narrowed to a slender, grooved limb, slightly 
crenulate-serrate almost to the base; costa rather pale, smooth on the back above, about 100 u 
wide at the base, one third the width of the leaf below, gradually wider up to the shoulder of 
the leaf, from which it tapers to the excurrent, denticulate, acute apex; leaf-cells elongate- 
rectangular, in the upper very narrow part of the blade scarcely 5 » wide and up to 40 yw long, 
in the basal part more or less hyaline, thin-walled, about 8 » wide and 100 y» long or longer; 
perichaetial leaves much like stem-leaves but longer, up to 4 mm., with a broader, clasping 
