110 DICRANACE/E. 



elongate, less serrate at margins and back, smooth or only faintly- 

 papillose. Upper cells larger, longer, sinuosely elliptic-rhomboid ; 

 not short, quadrate and angular. 



Var. 8. flexicaule Wils. (D. congestum var. flexicaule 

 B. & S., Braithw. Br. M. Fl.) Stem elongated, 4-8 inches, 

 decumbent at base, hardly tomentose ; leaves lax, long, falcato- 

 secund ; areolation as in var. y congestum. 



Var. e. robustum B. & S. Tall, robust, resembling D. 

 scoparium, hardly radiculose ; dull green above, blackish brown 

 below ; leaves hardly secund, broad, concave, shining, almost 

 entire, areolation as in var. congestum. 



Hab. Among grass and upon rocks, on mountains, frequent. The vars. (8, S, 

 more rare. The var. 7 very rare ; Ben Lawers. Fr. autumn. 



A very difficult and variable species ; the leaves may be smooth or highly papil- 

 lose, entire at margin or closely denticulate, narrow or broad at the base ; the fruit 

 varies incolour, in the amount of striation, in direction, and in form from broadly 

 ovate to narrowly cylindric. The form that must be looked upon as typical has very 

 narrow elongated flexuose leaves, from a narrow base, with rather broad, thick nerve, 

 about J- width of base, highly denticulate at back and margins above, with the cells 

 spinosely papillose ; areolation quickly becoming shortly rectangu'ar and almost 

 quadrate at the upper part of the leaf-base, rather regularly arranged, and more or 

 less uniform from thence to the apex, or somewhat elongated above ; in the var. 

 congestum the leaves are less elongated and flexuose, the nerve narrower and leaf-base 

 wider, and the cells, instead of quickly becoming short and sub-quadrate in the upper 

 part of the leaf-base, become very gradually shorter, elliptical, and sinuose, and it is 

 only quite high up in the subula that they become short, irregularly rhomboid or 

 elliptic, at the apex sometimes much elongated and larger ; in no part does it show 

 the minute more or less regularly sub-quadrate cells of typical D. fuscescens. I have 

 not, however, found the characters other than that of the areolation ascribed to D. 

 congestum by Braithwaite either constant in or peculiar to the congestum form, and I 

 do not think it can properly be accorded a higher rank than a variety. I gathered it, 

 for instance, very distinct in areolation and form of leaf-base, on the summit of Ben 

 Lawers in 1893, but with longer leaves much more narrowed above, than in the 

 plant described and figured by Braithwaite. 



Several other varieties have been described, of greater or less importance ; the 

 var. robustum, approaching D. scoparium in habit, with taller, stouter, hardly 

 tomentose stems, the leaves scarcely secund, is probably British. 



D. fuscescens may be recognised from D. scoparium by the narrower leaves more 

 crisped when dry, and the minute upper areolation. It much resembles D. 

 Scottianum, in some of its forms, but the basal areolation is longer, with the cell 

 walls perforated by pores, and the upper part of the leaf is almost always more or less 

 papillose and denticulate ; the form of the capsule distinguishes the species further, 

 but this is often absent, especially in D. Scottianum. 



C. APORODICTYON. 



13. Dicranum Scottianum Turn. (D. Scottii Turn., Braithw. 

 Br. M. Fl.) (Tab. XVIII. F.). 



Robust, in dense large rounded tufts, 1-3 inches high, dull or 

 yellowish green, tomentose. Leaves crowded, larger than in the 



