252 ORTHOTRICHACEyE. 



quite smooth, without strix, pale brown, when old whitish, oval 

 or oblong, very slightly constricted just below the peristome when 

 dry, abruptly contracted at the base into a very short seta. 

 Stomata superficial , near the base of the spore-sac. Peristome 

 double, outer of 16 opaque, highly papillose teeth, with a strong 

 median line and fine transverse striola?, when dry revolute and 

 touching the wall of the capsule with their tips ; inner of 16 

 erect, pale-yellowish, broad processes, often as wide as the teeth, 

 strongly papillose. Calyptra pale, with many yellow hairs. 

 Autoicous. 



Hab. Trees, frequent. Fr. early summer. 



This is one of the most distinct species, owing to the capsules being quite smooth. 

 They are more immersed than in any of the previous species except 0. Shawii. 



6. Orthotrichum Lyellii Hook, and Tayl. (Tab. XXXV. D.). 



Tall, robust, dark green or yellowish, in loose soft tufts, 1-2 

 inches high. Leaves spreading and recurved, when dry appressed 

 and almost straight, or loosely incumbent and somewhat flexuose, 

 elongate-linear from an oblong base, narrower than in most of 

 the species, long, flexuose, acute ; margin slightly recurved above 

 the base of the leaf on one or both sides for a variable distance, 

 but not to apex, faintly erose or denticulate at point, below 

 sinuose or irregular, with prominent distant papillae, especially 

 near the base. Cells at base narrow, rectangular, thin, the upper 

 distinct, oval or rounded-hexagonal, strongly papillose, the 

 papilla? large, not crowded, simple, conical or even linear ; the 

 nerve and lamina usually produce long, brown, jointed gemmae, 

 clavate, often branched. Capsule immersed or slightly emergent, 

 rather large, oval-oblong, with a tapering neck as long as itself ; 

 yellowish brown, dark brown when old, not or hardly contracted 

 below the mouth, but often slightly narrowed in the middle, 

 between the base of the spore-sac and the neck ; v/ith eight rather 

 indistinct ribs, when old deeply sulcate. Calyptra large, inflated, 

 pale, sparingly furnished with long hairs. Peristome double, the 

 outer of 16 teeth resembling those of O. leiocarpum and revolute 

 in the same way, inner of 16 processes, similar to those of that 

 species, but reddish. Stomata superficial, about the base of the 

 spore-sac. Spores large, 35-40 ju. Dioicous. 



Hab. Trunks of trees, common. Fruit rather rare, summer. 



The most robust of our species, and known at once by the long, flexuose, narrow 

 leaves, covered with reddish brown gemmae, often to such an extent that the older 

 leaves appear quite rough even to the naked eye. Biaithwaite mentions a marked 



