528 Key to the System of 



5646. Spore-caselets comparatively small, three-celled. 



Leaves quite minute, distantly scattered ; spore-caselets 



irregularly remote from each other. Fsilotum. 2133& 



21336. Branches dichotomously numerous, slender and tri- 

 angular. 



Usually dwarf, but occasionally rather elongated ; leaves 

 narrow and acute ; bracts very small, bisected, their 

 segments linear and pointed ; spore-caselets firm, pale- 

 yellowish, trigonous-globular, rather depressed, dehiscent 

 to the base into three valves, each of them inside with a 

 prominence along the middle. P. triquetrum. 





