DICRANELLA. 79 



Tribe 5. Dicranelleas. 



21. DICRANELLA Schp. 



The characters are those of the Tribe {v. p. 53). The small 

 size and narrow silky leaves of most of the species, with capsules 

 manifesting a somewhat uniform and distinct facies of their own, 

 render this a well marked genus. D. squarrosa alone of the 

 British species widely diverges from the usual habit, but it is a 

 plant which once identified will not easily be forgotten ; and the 

 identification of the others is rendered the more easy from the 

 fact that the greater number of the species are usually found in 

 fruit, and those which are most likely to be found barren are the 

 ones in which the vegetative characters are the most distinctive. 

 All the species are dioicous except D. crispa, which is both 

 dioicous and autoicous. 



I have not followed Braithwaite in adopting Mitten's division 

 into the two genera, Dicranella and Anisothecium, chiefly because 

 the distinctive characters are hardly constant enough to be quite 

 satisfactory, or clearly enough marked to be of much practical 

 value to the student. Thus D. cerviculata has the capsule smooth ; 

 on the other hand in D, (Anisothecium) Grevilleana it is lightly 

 striate ; while with regard to the nerve at base, there is practically 

 no difference between, for instance, that of some forms of D. 

 heteromalla and D. (Anisothecium) varia. 



{Leaves oblong-lanceolate, obtuse, squarrose 10. squarrosa 

 Leaves narrow-lanceolate or subulate 2 



/Seta yellow 3 



\Setared 4 



/Capsule strumose at neck 2. cerviculata 



3\Capsule not strumose, sulcate, with incurved mouth when dry /. heteromalla 



/Leaves subsquarrose, from a sheathing base 5 



4\Leaves erect or secund, base scarcely sheathing 7 



/Capsule erect, striate, furrowed when dry .3. crista 



->\Capsule cernuous, smooth or substriate only 6 



, / Leaves entire ; capsule faintly striate when dry 8. Grevilleana 



\ Leaves serrulate above ; capsule smooth 9. Schreberi 



/Capsule striate, furrowed when dry 8 



'\Capsule smooth 9 



( Leaves entire ; capsule subcernuous ; perich. bracts sheathing 4. secunda 



81 Leaves with a few teeth at apex ; capsule erect ; perich. bracts half-sheathing ... 

 \ 5. curvata 



{Leaves entire, cells narrow ; capsule cernuous 7. varia 

 Leaves serrulate above, cells larger ; capsule suberect 6. rufescens 



