Hypnace^.] 



156 



[Stereodon- 



20. STEREODON (Brid.) Mitt. 



Bryolog. univ. ii, 550 (1827). 



Procumbent or creeping mosses, growing on rocks, walls or trunks of 

 trees. Stems depressed or ascending, irregularly pinnate, paraph3'ses 

 only at base of branches. Leaves generally falcato-secund and arranged 

 distichously, diversiform, nerves two, short or obsolete, cells narrow and 

 linear, small and quadrate at angles, often coloured. Perich. bracts 

 plicate, capsule curved, cylindraceous, lid conical, endostonie more or less 

 perfect. — Der. a-repeo^ entire, oSous a tooth. 



This fine genus, embracing about 100 species, depends more on natural 

 habit than on structural differences, and the name was applied as a subgenus 

 of Hypnum by Bridel to species in which the processes of the endostome were 

 not perforated. This character is variable, and not sufficient to support a 

 genus, and IMitten adopted it for the group of which H. mpressiforme is the type. 

 The bifarious arrangement of the falcato-secund leaves is very striking, but 

 besides there are also in front, a central row with an intermediate row on each 

 side, of smaller non- falcate leaves, and a corresponding set at the back of the 

 stem, the longer falcate leaves are however so densely placed, that it is difficult 

 to observe the intermediate leaves which are much fewer, and often never 

 developed, 



Clavis to the species. 



Leaves bifarious, falcato-secund. 



Angular cells large, inflated. 



Acumen short, rather obtuse. 



subulate, long, serrulate. 



■ very long, entire. 



- many, small, quadrate. 



Leaf margin revolute nearly all its length. 



plane, entire. 



serrated in upper half. 



Leaves not auricled, angular cells hyaline. 



with rounded auricles of brown cells. 



■ recurved only at base. 



Leaves recurved. 



turned upward. 



■ not differing from the others. 



— spreading on all sides, secund at point of branches. 

 Autoicous ; with quadrate angular cells. 

 Capsule curved. 



erect. 



Dioicous ; angular cells not differing from rest. 

 Plant slender, leaves not plicate. 



robust, leaves plicate. 



Lindbergii. 



imponens. 



callichrotis. 



revolutiis. 

 Bambergeri. 



Caiiaritnsis, 

 circinalis. 



ciipressiformis. 



resupinatus. 



hamulosus. 



inciirvaUts. 

 polyanthos. 



subruftis. 

 rnfescens. 



Sect. A. DREPANIUM (Schimp.) Mitt. Capsule inclined, arcuate 

 processes of endostome pellucid. Leaves bifarious, falcato-secund. 



