ANDREiEA. 29 



4. Andreaea nivalis Hook. (Tab. VIII. H.). 



Tufts large, soft, 2-4 inches high, brownish. Stems slender, 

 flaccid, repeatedly branched, erect or decumbent, denuded at 

 base. Leaves rather distant, secund, at the apex of the branches 

 distinctly falcato-secund, soft ; the lower smaller, ovate-lanceolate ; 

 the upper gradually lanceolate from an oblong base, crenulate at 

 basal margin, irregularly sinuose or notched in the upper part ; 

 strongly papillose on both sides. Nerve narrower than in the last 

 species, \ to \ the width of leaf at base, reaching to apex or 

 vanishing just below ; prominent at back and papillose. Areola- 

 tion much paler and less opaque than in the other species, 

 irregularly rounded-quadrate above, at base more regularly 

 quadrate, not elongate. Dioicous ; male flowers gemmiform, 

 bracts numerous, imbricated, the inner nerveless ; perichstial 

 bracts elongate-lanceolate, resembling the leaves. Capsule open- 

 ing by 4-6 valves, rather large. 



Var. /3. fuscescens Hook. Stems more flexuose and flaccid, 

 with strongly falcate leaves of a brown colour. 



Hab. Alpine rocks, near the snow-line ; very rare, Grampians, Ben Nevis, 

 Ben Cruachan. The var. on Ben Nevis and Ben Macdhui. 



There is no difficulty in distinguishing A. nivalis from the other species of the 

 genus, but in the field it might possibly be passed over for the hepatic, Herberta 

 adunca, to which it bears a considerable outward resemblance. 



The var. fuscescens does not present very clearly definable characters, but is more 

 usually found fruiting, while the typical plant is more commonly found with male 

 flowers ; in Scandinavia the variety is the commoner form, and was therefore considered 

 by Zetterstedt the type of the species. 



This rare and interesting plant appears to be more at home on the Scotch 

 mountains than in any other place, but it is found on several of the highest ranges of 

 mountains on the continent. 



SUB-CLASS III. BRYALES. 



Spores and Columella (the latter absent in Archidium) 

 developed from the Endothecium, the Columella penetrating the 

 spore-bearing layer (Archesporium). Spore-sac separated from 

 the wall of the capsule by an air cavity. Capsule dehiscing 

 irregularly or opening with a lid. 



GRO UP A . NEMA TODONTEM. 



Peristome teeth solid, not transversely barred (very faintly 

 only in Buxbaumia) ; derived from several concentric series of 

 cells of the sporogonium. 



