MOSSES WITH A HAND-LENS 115 



included in other genera. Also it will frequently be more help- 

 ful to group species from different genera with a similar ap- 

 pearance rather than to put all species of a genus together. 



KEY TO the; hypnum family. 



1. IvCaves strongly turned to one side (secund) 2 



Leaves not secund 8. 



2. Leaves with a midrib 3- 



Leaves without midrib A- 



Z. Plants very robust, never fruiting; leaves wrinkled cross- 

 wise Hylocomium rugosmn. 



Plants slender to moderately stout; leaves often wrinkled 

 lengthwise, never crosswise Hooked Mosses 



4. Capsules wrinkled lengthwise when dry Hypnum curvifoHum. 



Capsules not appreciably wrinkled when dry 5- 



5. Capsules long-beaked; alar leaf cells much enlarged and 



hyaline Raphidostegium. 



Capsules not long-beaked; alar cells not much enlarged 6, 



6. Plants plume-like ; capsules strongly curved . . Hypnum crista-castrensis. 

 Plants pinnately branching but less plume-like; capsules erect 



or only slightly curved 7. 



7. Plants slender; dry capsule with mouth oblique H. reptile. 



Plants more robust, almost always on rotten wood; mouth of 



dry capsule not oblique H. iinponens. 



Plants growing on stones in cool brooks H. ochracewm. 



S. Growing in water Water-loving Hypnums. 



Growing in various situations, often in wet places hut not in 



water 9. 



9. Leaves with midrib; capsules very short and stout, not more 



than three times as long as broad .' 



Brachythecium and the Beaked IMosses. 



Leaves with midrib; capsules more than 3:1 10. 



Leaves without distinct midrib r i. 



10. Plants large, with a treelike habit; leaves appressed when dry; 



capsules cylindric and straight Climacium. 



Plants stout, suberect; leaves spreading when dry; capsules 



curved Hylocomium triqiietrum. 



Plants slender, creeping. ..Amblystegium and Hypnum chrysophyUum. 



Capsules erect and cylindric 15. 



Capsules more or less curved 12. 



Capsules wrinkled when dry Flagiothecium striatellum. 



Capsules smooth when dry 13. 



Leaves appearing flattended into two ranks Flagiothecium. 



Leaves not flattened into two ranks 14. 



Plants bright golden green, usually growing on soil 



Hypnum Schreberi. 



Plants green, usually growing on decaying wood-.-H. Haldanianum. 

 Plants usually growing on bark of trees 



Amblystegium adnatum and Pylaisia. 



Plants usually growing on soil or decayed wood or over 



stones Entodon and Hypnum Haldanianum. 



HYPNUM. 



In one section of this composite genus the leaves are all 

 turned to one side (secund), and the branching is more or less 

 regularly pinnate, giving the plants a plume-like appearance in 

 many cases. The leaves are without midrib. This section is 

 often called Hyt^iiuut proper. Two of the most common and 



