2 



AMBLYSTEGIUM. 44 1 



any plant which belongs to it, with very few exceptions, when the 

 fruit is present ; these are the curved, sub-cylindrical, narrow 

 capsule, non-rostrate lid, smooth, short cells and non-complanate 

 leaves ; these characters will distinguish Amblystegium from any 

 of the previously described pleurocarpous mosses. In the case 

 of Hypnum it is very rare that the cells are short and wide as in 

 the present genus, but in these few cases, as well as in the case of 

 barren plants, experience will sometimes alone make it possible 

 to recognise a species as belonging here, at sight, or without care- 

 ful examination. As a consequence of the character of the areola- 

 tion, the leaves in this genus are rarely glossy as is usually the 

 case in the preceding genera of Hypnacese. 



{Ls. nerveless ; plant very small and slender 2 

 Ls. single-nerved half-way or more 3 



/Capsule erect ; ls. erecto-patent ; dioicous /. Sprucei 



\ Capsule cernuous ; ls. sub-secund ; autoicous <*. confervoides 



/Angular cells of ls. hyaline, forming distinct auricles 4 



■'(.Angular cells not forming distinct auricles 5 



{Stem radiculose and with paraphyllia; nerve thick 7. filicznum 

 Stem scarcely radiculose, without paraphyllia 8. curvicaule 



/Nerve slender, reaching £ or f up leaf 6 



5\Nerve reaching nearly or quite to apex 7 



.-/Ls. under \ line long, ovate-lanceolate 3. serpens 



\Ls. over \ line long, cordate-ovate 9. Kochii 



fLs. oblong-lanceolate, sub-acute ; capsule suberect 6. fluviatile 



' \\js,. acuminate, from ovate or cordate base ; capsule arcuate 8 



o /Plant slender, fixed by numerous radicles ; ls. spreading 4. varium 



\ Plant larger, scarcely rooting ; ls. more or less secund .5. irriguum 



1. Amblystegium Sprucei B. & S. (Leskea Sprucei Bruch). 



(Tab. LV. M.). 



Extremely minute, forming small patches of a pale green; 

 stems filiform, very delicate, irregularly branched, fragile ; leaves 

 distant, erecto-patent when moist and when dry, minute, less than 

 "% line in length, ovate-lanceolate on the stems, lanceolate- 

 acuminate on the branches, all narrowly acuminate, nerveless, 

 plane at margin and entire or obsoletely denticulate or sinuolate ; 

 cells irregularly hexagonal-rhomboid, 2-5 times as long as broad, 

 pellucid, with firm walls ; at basal angles slightly wider and sub- 

 rectangular, but not distinct. Seta very short, capsule minute, 

 erect or suberect, hardly curved, obovate, somewhat turbinate 

 when ripe and empty ; inner peristome without cilia. Dioicous. 



Hab. Shady subalpine rocks, very rare ; North of England ; Scotland. Fruit 

 very rare, in summer. 



The most minute of our pleurocarpous mosses, and only approached for delicacy 

 by the next species, and occasionally by slender forms of A. serpens, and of 



