146 GRIMMIACE/E. 



The small hoary tufts resemble G. puhhiata, but the fruit when present is quite 

 different. The short, wide, basal areolation will readily distinguish it from all the 

 allied species except the next, which it very closely resembles ; the distinguishing 

 characters are pointed out under that plant. 



21. Grimmia alpestris Schleich. (G. t/rc^erzjuratz., Schp.Syn.) 



(Tab. XXIII. C). 



Very near G. montana, differing in the leaves, slightly more 

 erect and straight when moist, rather shorter and broader at the 

 points, the margins more inflexed, and more strongly thickened, 

 the hair-point rather shorter and smoother ; perichaetial bracts 

 larger, broader, half-sheathing. Capsule on a rather longer seta, 

 smaller, rather narrower, oblong-cylindric ; lid conical, short, 

 obtusely pointed. Dioicous or rarely autoicous. 



Hab. Siliceous rocks in alpine districts. Very rare. Near Ballater. Clova. 

 Fr. spring. 



G. alpestris, besides being closely allied to G. montana, is liable to be confused 

 with lax forms of G. Doniana, which however has longer and narrower basal cells 

 and a mitriform, not cucullate, calyptra. 



22. Grimmia leucophsea Grev. (G. campestris Burchell, 



Braithw. Br. M. Fl.) (Tab. XXIII. D.). 



In loose wide tufts, easily breaking up, dull green, hoary 

 above. Leaves crowded, gradually larger towards the apex of the 

 branches, closely and regularly appressed when dry, concave, 

 short, {\-\ line), very broad, triangular-oval or oval-oblong, 

 broad at the apex, terminating in a very long, finely denticulate , 

 flattened hair, which is very wide at the base and decurrent, 

 often longer than the leaf ; margin. plane, not thickened; nerve 

 thin, flattened. Upper cells roundish-quadrate, very chloro- 

 phyllose, the basal rectangular, more diaphanous, a few rows 

 next the nerve slightly elongate and hyaline, the rest shorter 

 (often broader than long), more quadrate ; all slightly incrassate, 

 and non-sinuose. Capsule hardly exserted, erect, oblong, rather 

 large, smooth, thick-walled; calyptra mitriform, lobed; lid 

 rostellate. Dioicous. 



Hab. Dry siliceous rocks in warm situations. Not common. Fr. spring. 



A very distinct plant, the broad, short leaves having no resemblance to those of 

 any of the species of this Section, except G. pulvinata and G. orbicularis, both of 

 which differ in the fruit and in the recurved leaf-margins. The broad, white hair- 

 points are very conspicuous. 



It is a southern and lowland rather than an alpine plant. 



