BARBULA. igi 



/Basal cells distinct, rectangular, more or less elongated 13 



\ Cells almost uniform to base 15 



./Upper cells more or less rounded-hexagonal ; peristome short, straight.. .6. rigidula 

 ■'(.Upper cells quadrate ; peristome long, twisted 14 



/Ls. linear-lanceolate, long, spreading ; capsule cylindric 7. cylindrica 



4\Ls. lanceolate, short, straight, more acute ; capsule oblong 7*. vinealis 



/Ls. erecto-patent, some (at least) sub-obtuse ; robust ; peristome short... j - . spadicea 



-'V.Ls. squarrose, more acute ; slender ; peristome long, twisted 16 



g/Ls. trifarious, recurved, reddish, with short points 4*. reciirvifolia 



\Ls. less recurved, more tapering, lurid green 4. fallax 



1. Barbula lurida Lindb. (Didymodon luridus Hornsch.) 



(Tab. XXIX. A.). 



Short, rarely more than an inch in height; in dense tufts, 

 dull deep green, frequently tinged with brown, pale brown below; 

 stems rather slender, slightly branched. Leaves erecto-patent, 

 -when dry erect, closely imbricated (especially the upper ones), 

 hardly twisted ; concave, ovate-lanceolate , or deltoid-ovate, 

 quickly narrowed to a wide, obtuse or slightly acute point ; margin 

 recurved below on one or both sides, slightly thickened above ; 

 nerve thick, strong, vanishing just below the apex or reaching to 

 the point; cells small, distinct, hexagonal or rounded-quadrate, 

 rather incrassate, at the extreme base hardly altered, a little 

 larger and a few slightly elongated ; all smooth or faintly mam- 

 mosely protuberant. Capsule on a purplish seta, oblong or 

 shortly cylindric, lid conical-rostellate, often oblique ; peristome 

 teeth not united at the base, short, slender, rather irregular, simple 

 or cleft above, pale yellowish. Dioicous. 



Hab. On rocks, most frequently calcareous, and stumps ; more commonly, but 

 by no means always, near water. Fr. very rare, winter. 



Although somewhat variable in habit and structure, this species may generally 

 be known by its short, broad, concave, usually obtuse leaves, closely imbricated when 

 dry ; B. tophacea differs in its narrower leaves and more elongated basal areolation ; 

 B. fallax var. brevifolia very much resembles it, and when barren can sometimes 

 hardly be distinguished except by its more straggling, laxer habit, somewhat softer 

 leaves and distinctly narrower nerve. B. lurida is more rigid in its growth than most 

 of the allied species. I have seen barren forms of Ceratodon purpureus which much 

 resemble it, but under the microscope the resemblance would disappear. 



The leaves vary much in form, in the degree of recurving of the margins, and in 

 the width of their points ; one form has the margins widely recurved to the apex, 

 which is very obtuse and rounded. Several continental species are very much like 

 the present in the outline of their leaves, but differ in other points. 



I have found B. lurida in many places in the midland counties of England, but 

 invariably sterile. 



2. Barbula rubella Mitt. (Bryum rubellum Hoffm. ; Didy- 



modon rubellus B. & S., Schp. Syn.) (Tab. XXIX. B.). 



Taller, 1-2 inches high, in large soft patches, bright or deep 

 green above, below bright rusty red ; stems slender, branched. 



