136 GRIMMIACEyE. 



dry, pale brown, lid conical, obtusely apiculate ; peristome teeth 

 irregularly divided and pierced at the apex, red. Dioicous. 



Hab. Siliceous rocks on mountains ; not common. Fr. autumn. 



There is a peculiar facies about this plant by which it may generally be known in 

 the field ; this is partly due to the dense level tufts, dark grey or blackish, only the 

 few uppermost leaves on^ each stem forming minute separate points of green ; and also 

 to the stems falling away from one another upon gathering, so that it is difficult to 

 preserve good tufts ; but the feature by which it is most readily known is the spiral 

 twisting of the leaves when dry, giving the stems exactly the appearance of miniature 

 ropes. In G. incurva the leaves though twisted are not appressed, and hence do not 

 present this appearance ; in G. torquata — which in colour and texture is very 

 different — the leaves are much less closely appressed, often more or less twisted upon 

 themselves, and rarely, therefore, present the strict, close rope-like appearance of the 

 present plant. The hair-points in the present plant are almost always longer than in 

 that. The shorter and broader leaves will usually distinguish it from G. trichophylla 

 and the smoothish hair points from G. Miihlenbeckii. 



The more luxuriant the stem and leaves the more pronounced is the cable-like 

 twisting, and I have dwarf specimens in which it is hardly perceptible. 



In the old leaves, as is often the case with members of this genus, the upper cells 

 are blackish, very obscure, and hardly distinguishable. 



7. Grimmia torquata Hornsch. (Tab. XXI. K.). 



In large, swollen cushions, 1-3 inches high, soft ; stems 

 slender, branched, coherent, bright or yellowish green above, 

 reddish brown below. Leaves erecto-patent, when dry incurved, 

 twisted and spirally contorted, very small and narrow, oblong- 

 lanceolate, carinate, the lower hairless, the upper with a very 

 short, flat hyaline point ; margin plane or lightly reflexed, nerve 

 thin, areolation resembling the last, but more incrassate and 

 sinuose, pellucid. Seta longer than in the last, arcuate when 

 young, erect and flexuose when ripe, pale yellow ; capsule oval, 

 when mature oblong, pale brown, irregularly striate longi- 

 tudinally when dry, calyptra small, lid with a slender straight 

 beak ; peristome teeth yellow, short, irregularly bifid. Dioicous. 



Hab. Shaded alpine rocks ; not common. Barren in Britain. 



The fruit of this plant was found for the first time in the Rocky Mountains, by 

 Leiberg, in 1888, and is elsewhere unknown. The barren plants frequently produce 

 filamentous or globose clusters of cells on the leaves, and these gemmae serve to repro- 

 duce the plant, as in so many mosses. When once known it is a species easily 

 recognised ; in aspect it resembles Anactangium compactum rather than any of the 

 species of its own genus, and the extremely short hyaline point is hardly visible except 

 under the microscope. The leaves are more lax and less closely appressed when dry 

 than in the last, so that, except in stunted specimens, the twisting of the leaves is.less 

 rope-like and pronounced, and the upper leaves are usually less spirally arranged and 

 more irregularly incurved. The whole texture, too, is softer, and the stems though 

 easily separable do not fall apart of their own accord when gathered. The colour, 

 moreover, is as a rule quite different. The leaves are about equal in length, but 

 rather narrower. 



