234 THE JOURNAL OF BOTANY 



Dominant. Lycoj^odium alpinnm L. 



Bhacoviitrium lamujinosum Polytriclium aljnnum L. 



Brid. Cetraria aculeata Fr. 



Abundant. Cladonia cervicornis Schaer. 



Cladina rangiferina Nyl. ^- r acil i s B.o&n^ 



Cetraria crispa Nyl. C. macilenta Hoffm. v. coronata 



Alectoria nigricans Nyl. ^ ' 



Eare. 



Frequent. Cladonia destricta Nyl. 



Cladina sylvatica Nyl. Lecanora tartarea Ach. 



C. uncialis Nyl. Cladonia hellidiflora Floerke. 



C. uncialis Nyl. v. ohtusata Nyl. C. squamosa Hoffm. forma. 

 C. uncialis Nyl. v. turgesccns G- degencrans Floerke. 



Cromb. G- degcnerans Floerke v. plcolc- 



Cladonia deformis Hoff'm. pidea Nyl. 



Empctriim nigrum L. Alectoria ochroleuca Nyl. 



BcBomyces ariiginosus DC. 

 Occasional. Bilimhia melana Arnold. 



Hypnum Schreberi Willd. Hjfpnum cuprcssifornie L. 



Ckf/07Ma furcata Hoffm. ^7/ ocom4W7;Worcm^t B. & S. 



Dicramim fuscescens Turn. PtiUdmm ciliarc Hampe. 



Carea; n^eVZa Good. ^^^^^^'"^ hP^orum Fr. 



The majority of the species in this list ascend considerably 

 above the 3000 ft. contour. The vegetation of the plateau gravel 

 has been described as cushion-like or crustaceous ; that of the 

 present association may be said to be mat- or carpet-like. The 

 dominant moss has long, much divided, trailing stems, which are 

 interlaced together by numerous short hooked branches and long 

 leaves. This clinging of the stems does not always prevent strong 

 gales from tearing up large sheets of the carpet. Bare patches 

 formed in this manner revert to the moss-lichen stage until the 

 Bhacomitrium reassumes dominance. The apices of the leaves of 

 this moss are devoid of chlorophyll, papillose and eroso-ciliate, 

 thus presenting innumerable small prominences for the reception 

 of dew. It will be observed that this echlorophyllose area is as 

 papillose as the rest of the leaf, and therefore we cannot in this 

 instance regard the papillae as simply designed to shield the 

 chlorophyll from the sun, or to prevent evaporation, which is 

 usually accepted as their raison d'etre. The condensed moisture, 

 or, during show^ers, rain-water, runs down to the thick underlying 

 mass of old stems and leaves, whicla hold it like a sponge. Still 

 lower a layer of humus is rapidly formed. Most of the flowering 

 plants and other dependent species cower beneath the shelter of 

 the moss, only in favourable seasons protruding their growing 

 tips, and, as is apparent from the paucity of individuals as well 

 as species, often suffering severely for their temerity in so doing. 

 The smaller mosses and lichens, especially those of effuse hori- 

 zontal growth, have no chance, and are rapidly smothered, the 

 erect fruticulose lichens greatly preponderating. Cladina and 

 CladonicB with elongate podetia are frequent, presenting often 



