CYNODONTIUM. 75 



Var. /3. compactum Schp. Tufts short, dense; leaves 

 crowded, more erect, shorter, from a smaller base. Capsule 

 smaller, less solid, short. 



Hab. High alpine rocks. Rare. The var. B on the higher Grampians. Fr. 

 late summer. 



The leaf-base in C. virens is sometimes oblong, hardly wider above than at the 

 insertion, and very gradually contracted into the limb, which is usually short, and 

 rather quickly narrowed to the apex. In C. Wahlenbergii, the leaf-base is very short 

 and broad, widening considerably upwards from its line of insertion, then suddenly 

 narrowing (so as to form a shoulder), into the much narrower and longer, linear- 

 subulate limb. Although however there is a wide distinction between these two 

 extreme forms, there are found many intermediate links, leaves of various forms often 

 occurring in the same stem ; indeed I have never examined a tuft of C. virens with- 

 out finding some leaves that showed an approach to the leaf-form of C. Wahlenbergii. 

 The var. compactum too, while usually clearly referable to the sub-species, has the 

 leaves in several specimens which I have examined, far from showing the typical 

 Wahlenbergii form, being indeed intermediate between the two. I have therefore 

 felt compelled to deny C. Wahlenbergii specific rank, although in its most extreme 

 form, did that alone exist, it might well lay claim to such a position. 



19. DICHODONTIUM Schp. 



Plants loosely tufted, usually growing near rocky streams ; 

 leaves spreading or squarrose, broad, opaque, papillose. Capsule 

 smooth, thick- walled, peristome large, dicranoid. 



The two species of this genus are very distinct from the rest 

 of the Order in the broad, obtuse, papillose leaves with plane 

 margins, at least in the upper half. They are indeed more likely 

 to be referred by the beginner to Tortulaceae than to Dicranaceae. 

 The peristome is quite distinct, but more often than not the plants 

 are barren. Few of the species of Tortulaceae, however, for 

 which the student is at all liable to take either of these plants, 

 have the spreading, denticulate leaves of D. pellucidum or the 

 coarsely serrate leaf margins of D. flavescens. 



Oreoweisia serrulata Schp. has been recorded from Ben 

 Lawers by Dr. Stirton, but its claim to be regarded as British is 

 very doubtful. It is a native of the Austrian Alps, and is 

 monoicous, with narrow, serrulate, obtuse leaves, having the 

 basal areolation thin and hyaline, the upper obscure and highly 

 papillose ; the habit is more slender than that of Dichodontium. 



( Leaves rather obtuse, serrulate ; capsule cernuous /. pellucidum 



\ Leaves acute, sharply serrate ; capsule suberect 2. flavescens 



