172 BEYACE^. [Orthotrichum. 



18. O. brachytrichum, Schimp. Plants short, about one 

 cm. long, in pale green tufts, blackish and streaked with yellow 

 when old: leaves oblong-lanceolate, the upper longer, linear- 

 apiculate, acutely carinate, subrevolute or reflexed on the bor- 

 ders : male flowers terminal on separate branches : calyptra pale 

 straw-color, bearing a few short hairs at the apex : capsule thin, 

 oblong, subcylindrical in connection with a somewhat long 

 collum, light brown passing to yellow, with 8 dark-colored stride, 

 ribbed when dry ; teeth 8, small, bigeminate, entire, with large 

 punctulate areoles ; cilia 8, smooth, as long as the teeth, — Lesq. 

 & James, Proc. Am. Acad. xiv. 140. 0. obtusi/olium, Druram. 

 Muse. Amer. n. 157. 



Hab. On trees; Upper Canada to the Rocky Mountains (Drummond). 



19. O. strangulatum, Beauv. Plants very small, in small 

 loose dirty green tufts, half a cm. long: leaves half-spreading 

 when moist, linear-lanceolate from an oblong base, angularly 

 pointed or blunt at the apex, revolute on the borders ; ujiper 

 ai'eolation round, small, close, sliglitly paj^illose, long and quad- 

 rangular toward the base ; pericha^tial leaves longer, erect, 

 somewhat sheathing : calyptra nearly naked : cajisule sliort- 

 pedicelled, half-emergent, oblong-obovate, distinctly 8-costate 

 when dry, strongly constricted under the orifice, dirty brown 

 when old ; lid conical, obtusely apiculate ; teeth 8, bigeminate, 

 dirty yellow, granulose, reflexed when dry ; cilia strong, as long as 

 the teeth, formed of a double row of cells. — Prod. 81 ; Schwaegr. 

 Suj)pl. ii. 2. 33, t. 54 ; Sulliv. Muse. Allegh. n. 128, Mosses of U. 

 States, 33, and Icon. Muse. 57, t. 36. 



Hab. On trees, rarely on rocks; very common. 



* * * * Capsitle exserted, long-cylindrical lohen dry. 



20. O. tenellum, Bruch. Plants very small, tufted : lower 

 leaves broadly lanceolate, the upper longer-lanceolate, revolute 

 on the borders, acute or blunt ; areolation large, not papillose : 

 calyptra long and narrow, yellowish green, I'arely pilose : cajisule 

 emergent, oblong-cylindrical, decurrent to a long collum cover- 

 ing the whole length of the pedicel, broadly reddish-striate, 

 broadly costate and constricted under the orifice when dry and 

 empty; lid short; peristome short, the teeth bigeminate, bifid 

 at the apex, pale; cilia a little shorter, of a double series of 

 cells. — Brid. Bryol. Univ. i. 786; Bryol. Eur. t. 212. 



