448 HYPNACE^. 



base; at basal angles suddenly dilated, hyaline or orange, large, 

 rectangular, forming ■wide, decurrent auricles. Paraphyllia 

 none. Fruit unknown. 



Var. (3. strictum Dixon n. var. Stems and branches prostrate, 

 rigid, elongated, 2-4 inches long, much denuded except at the 

 tips; branches straight, not or scarcely curved, acute and 

 cuspidate at apex ; leaves sub-scariose, glossy, not plicate, rigid, 

 oblong-lanceolate , or narrowly ovate-lanceolate ; areolation 

 narrower, elliptic-hexagonal or linear-rhomboid, 6-8 times as 

 long as wide, very suddenly dilated at decurrent angles, large, 

 inflated, bright orange in the older leaves. Tufts deep orange- 

 brown, dark brown below. 



Hab. Wet rocks, Ben Lawers, alt. 3,500ft. (Dixon, i8gs). The var. strictum 

 with the type. 



This moss, which has been very perplexing to systematists, was gathered by me 

 near the summit of Ben Lawers in the summer of 1893, ar) d by a curious coincidence 

 was gathered on the same mountain, independently, by the Rev. H. G. Jameson, very 

 shortly afterwards. Mr. Jameson's specimens appear to belong to the type, agreeing 

 exactly, as do some of mine, with the specimens from le Sentis, Switzerland, published 

 in the Musci Gallise. No. 786, by Culmann, and also with Breidler's from the Tyrol, 

 as well as with Juratzka's original description, given in the very lucid article on this 

 species by Venturi in Rev. Bry., 1881, p. 82. The greater part of my specimens, 

 however, while incontestably belonging to the species in question, are so different in 

 habit, texture, leaf-form, and areolation that I have thought them fully deserving a 

 varietal name ; the cells are of the same character precisely, but longer and narrower, 

 rarely less than six times as long as broad, while in the type they rarely attain this 

 proportion ; the leaves are much narrower, from twice to three times as long as broad, 

 while in the type they range from once and a half to twice as long as wide, rarely 

 exceeding the latter proportion. The habit, too, is much more rigid and very 

 different. 



The affinities of this plant are very doubtful ; the general consensus of opinion 

 places it near A. filicinum, although various authors have placed it in the sections 

 Harpidium, Limnobium, and Calliergon of the genus Hypnum ; Lindberg, indeed, 

 makes it a sub-species of A. filicinum, but I cannot think this view will hold ; the very 

 different appearance, the absence of paraphyllia, the characteristic acumination of the 

 leaves, and the very different nerve remove it from all forms of that very polymorphous 

 plant. The nerve, though comparatively strong, is much less so than in A. filicinum 

 and always ceases almost or quite at the base of the acumen ; the acumen itself is very 

 abrupt and markedly different from the gradual acumination of A. filicinum and most 

 of the allied plants ; it forms, indeed, such a constant and marked character that 

 Venturi is probably right in thinking that Schimper's description of the leaves as 

 gradually acuminate points to a different plant, specimens of a Harpidioid Hypnum 

 having frequently been mixed with and labelled as the present species. It is probable 

 that no definite agreement will be arrived at until the fruit is found ; it may be worth 

 while to point out that in habit, branching, leaf-form, and areolation there is a some- 

 what close resemblance between the present plant and Brachythecium Nova-Anglia 

 Sull. ; and this is somewhat emphasised by the occurrence of an intermediate plant, at 

 present undetermined, which I have received from N. America, and which has been 

 referred by some bryologists to the Section Cratoneuron of Hypnum as near H. 

 filicinum, and by others placed near Brack. Novtc-Anglia. It is not at all impossible 

 that the present species may ultimately prove to be a Brachythecium. 



A. curvicaule may be readily known by the more or less abrupt acumen, long 

 nerve and short areolation with abruptly dilated hyaline auricular cells, from the other 



