152 GRIMMIACE/E. 



obtuse, without a hyaline point, thin, pellucid, lightly plicate at 

 base; margin strongly recurved ; nerve very thin and faint, ill- 

 defined, vanishing below the apex ; cells all long, narrow and 

 sinuose, even those in the upper part of the leaf 3-5 times as long 

 as broad and finely papillose, a single row, rarely two or three, of 

 quadrate or rectangular hyaline cells forming a marginal band at 

 the basal angles. Seta short, rather thick, brown ; calyptra 

 papillose over the whole subula ; capsule oblong, dark brown, 

 thick-walled ; peristome teeth divided to base, divisions filiform. 



Hab. Rocks, usually in subalpine situations. Frequent. Fr. spring and 

 summer. 



There is nothing very distinctive in the appearance of this species at first sight, 

 but a more careful examination shows the leaves to be quite green to their tips, with 

 no trace of a hyaline point ; and its slender habit and narrow leaves will distinguish 

 it from the last species, as will its mode of branching from the ordinary muticous- 

 leaved form of R. heterostichum ; in doubtful cases the cells, elongate to the apex of 

 the leaf, and the very faint nerve will abundantly distinguish it, while the total absence 

 of hair-point, dark seta, and larger, brown, pachydermous fruit will equally separate 

 it from R. ramulosum. 



5. Rhacomitrium ramulosum Lindb. (Grimmia ramulosa 



Lindb., Braithw. Br. M. Fl. ; R. microcarpon Brid., Schp. Syn.) 



(Tab. XXIII. L.). 



In low pale green or yellowish tufts, slightly hoary; stems 

 slender, nodose, with very numerous short obtuse lateral branch- 

 lets. Leaves shorter than in the last species, thin and pellucid, 

 lanceolate from an ovate base, rather broad at the point, with a 

 flat, denticulate hair-point variable in length, usually very short ; 

 margin recurved, not thickened above, nerve stronger and more 

 distinct than in the last, percurrent ; cells all elongated and 

 extremely narrow, 3-6 times as long as broad at apex. Seta 

 short, pale yellowish ; capsule very small, pale, thin-walled, oval 

 or oblong ; calyptra papillose above ; peristome teeth short, deeply 

 divided almost to base. 



Hab. Dry mountain rocks. "Highlands" (Herb. Hook.). Fr. autumn. 



The only claim to its being considered a native of Britain rests upon a specimen 

 of this plant in Hooker's Herbarium, labelled as above. Boulay and Husnot unite it 

 with R. heterostichum as a variety, but the reason for so doing is difficult to see, so 

 long, especially, as R. sudeticum is maintained as a separate species ; I cannot but think 

 that the uniformly elongated areolation in the present plant is a character of greater 

 importance than any which separates the former from R. heterostichum. In habit .A". 

 ramulosum resembles R. fasciculare to some extent, and in the densely nodose branch- 

 ing it even approaches R. canescens, while the hair-point is occasionally so developed 

 as to render the plant quite hoary ; the areolation and the presence of a hyaline point 

 make it easy of recognition ; in the fruiting characters it is near R. sudeticum, but the 



