BLINDIA. 87 



areolation longer than in the last species, frequently with a slight 

 sigmoid curve, the cell-walls often becoming very incrassate in 

 the older leaves, rendering the cells very narrowly linear ; angular 

 cells large, orange brown. Capsule on a longer seta, exserted 

 though often hidden by the leaves of the innovations, variable in 

 shape, longly or shortly oval-pyriform, with a short wide neck, 

 slightly contracted below the mouth when empty, so as to appear 

 urceolate ; peristomate. Lid shortly and obliquely rostrate ; 

 peristome teeth broad, deep red, erect or incurved when dry. 

 Dioicous. 



Var. trichodes Braithw. (Dicranum trichodes Wils. MS.) 

 Leaves more secund, from a much shorter leaf-base, \-\ length of 

 leaf, more abruptly narrowed into the long, very narrow, finely 

 acute, denticulate subula, the apical cells of which are elongate- 

 linear, angular cells fewer ; capsule shorter, peristome teeth short, 

 truncate. 



Hab. Mountain rocks, especially near water, common ; the var. $ on rocks by 

 waterfalls, etc., rare. Fr. summer. 



A somewhat variable plant in the relative size of its parts, but always identified 

 at once by the yellowish leaves with deep orange basal angular cells ; there is a 

 peculiar facies which after a little practice makes it an easy plant to recognise in the 

 field, but this is not easily described ; it is partly due to the somewhat rigid, glossy, 

 not at all flexuose leaves, smaller and shorter for the size of the plant than in most 

 species of Campylopus and Dicranum. 



The position and limits of the var. trichodes are very difficult to define. In 

 Wilson's original specimens the apex of the subula is quite different in areolation from 

 ordinary B. acuta, the cells being very long and narrow, and in only one or two rows 

 at the tip, which is consequently very acute ; whereas in B. acuta the apex is more or 

 less wide and rounded, with short, irregular cells, and with crowded denticulations, 

 and even when, as occasionally happens, it is very acute, the areolation is still the 

 same. If this be held a distinguishing character, and it appears a fairly constant one, 

 then the greater number of specimens labelled " B. trichodes" must certainly be 

 referred to the type, including for instance Nowell's plant from Todmorden, specimens 

 of which I have, through the kindness of Dr. Braithwaite, in my herbarium. In this 

 case it will be probably found that the true var. trichodes is always a very small plant, 

 as described by Philibert (Rev. Bry., 1884, p. 90). I have gathered this form barren 

 on the Sow of Athol, Perthshire, and the greater number of the leaves show exactly 

 the characteristic areolation of Wilson's plant ; though a few leaves show some 

 approach to the normal acuta form. If, on the other hand, with most authors, the 

 apical areolation is left out of the question, we can set hardly any satisfactory limits 

 to the variety ; for forms of Blindia acuta are very frequent (especially on rocks 

 constantly exposed to the action of water, as beneath waterfalls) which show the form 

 of leaf exactly characteristic of ' trichodes? but with the apical areolation, and the 

 fruit of B. acuta. The form of the leaf is therefore, alone, not a character of import- 

 ance, and if the form ' trichodes ' is to be maintained, whether as a variety, sub-species 

 or species, it must, I think, be confined to the dwarf, slender plants with the peculiar 

 areolation above described, and with the fruit as defined by Braithwaite. 



23. DICRANOWEISIA Lindb. 



Plants in dense cushions ; leaves crisped when dry, entire, 

 with the angular cells more or less distinct. Capsule erect, 



