114 DICRANACE/E. 



The distinctly papillose and strongly denticulate shorter leaves, much crisped 

 when dry, abundantly distinguish this plant from the allied species. The margin is 

 frequently minutely denticulate almost to the base by the projecting transverse walls 

 of the cells. The apex is wider than in the preceding species or indeed than any of 

 this section. The small deep green cushions with strongly crisped leaves are not 

 unlike those of Dicranoweisia cirrata, but under a strong lens the denticulations of 

 the subula are apparent. 



18. Dicranum uncinatum C. M. (Thysanomitrium uncin- 



atum Harv. ; Dicranodontium circinatum Schp., Syn.) 



(Tab. XIX. D.). 



Golden green, in lax patches, 2-5 inches high, robust. Leaves 

 glossy, laxly placed, regularly falcato-secund, in the upper part 

 of the stem circinate, hardly altered when dry ; the upper very 

 long, from a short, broadly oblong sheathing base, hardly \ the 

 length of the leaf, quickly contracted into a lanceolate-subulate 

 channelled limb, which gradually narrows to a long setaceous 

 point. Nerve \-\ width of base, very thin, of three layers of 

 small cells, at apex finely denticulate at back, excurrent in a 

 spinulose arista ; margin at base entire, near the summit finely 

 denticulate. Angular cells wide, very thin and hyaline or pale 

 brown, occupying all the base to the nerve, very distinctly marked 

 in the older leaves from the rest of the cells ; above these the 

 cells are golden green, the median widely rectangular with dark 

 walls, gradually narrowing upwards, the outer in several rows of 

 very narrow linear cells forming a broad marginal band becom- 

 ing wider as it passes upwards ; about the shoulder of the leaf- 

 base the cells become uniform, narrow-linear, obscure, continuing 

 so to the summit, a single marginal row usually being rhomboid 

 or elliptical with projecting oblique walls forming minute denticula- 

 tions which become more distinct towards the apex. Seta short, 

 flexuose or straight ; capsule erect, cylindric, dark brown ; 

 peristome teeth cleft half way, the divisions subulate. 



Hab. Mountain rocks and grassy places, rare. Fruit very rare, not found in 

 Britain. 



A very fine plant, resembling a small form of D. majus in aspect. It differs from 

 D. longifolium in the narrower nerve of very different structure, and in the larger size 

 and more robust habit. D. dsperulum is very nearly allied, but differs in the less 

 falcate more flexuose leaves, the margin sharply and closely denticulate from the base 

 of the limb, etc. 



The distinctive areolation of the leaf base is best seen in the older leaves, and 

 their rich and varied colour makes them a beautiful object under the microscope. 



The calyptra appears to be slightly fringed at base, in this respect showing an 

 approach to Campylopus. 



