MOSSES WITH A HAND-LENS 167 



B 



1. Leaves complicate-bilobed, lobes nearly equal or the lower 



larger giving the appearance of four rows of leaves of 

 which the two upper are incubous and the two lower suc- 



cubous : -Scapama. 



Leaves not complicate-bilobed, in some cases toothed or divided. ... 2. 



2. Leaves entire or slightly emarginate 3- 



Some or usually all of the leaves strongly toothed or lobed 8. 



3. Leafy stems about J inch wide, leaves oblong, plainly over- 



lapping; on ground and over mosses 4- 



Plants about J inch wide, many leaves not overlapping, floating- 

 aquatic Chiloscyphus poly ant hos var. rivularis. 



Leafy stems ^ inch wide or less; leaves more nearly circular 6. 



4. Plants ascending, growing on stones and very wet soil near 



brooks, dark green; leaves round-obovate Plagiochila. 



Plants closely applied to substratum of rotten wood, humus, 

 or soil, sometimes creeping over other hepatics and mosses; 

 light-green; sometimes turning dark when dried; leaves 

 oblong to oblong-ovate 5- 



5. Perianth pear-shaped to tubular, abruptly narrowed to the 



minute opening Jungermanma lanceolata. 



Perianth three-angled, plainly lobed at the top Chiloscyphus. 



6. Leaves plainly margined, apices curved upwards toward each 



other when dry . 7- 



Leaves not margined, apices reflexed when dry Jamesoniella. 



Leaves not margined, apices curved upwards (incurved), 



when dry Odontoschisma. 



7. Leaves obliquely attached to the stem, bordered by a single 



row of very large square cells which are easily seen with 



high power lens . . .Nardia crenulata. 



Leaves attached to the stem almost parallel with its long 

 axis, bordered by several rows of denser cells with thicker 

 walls Odontoschisma. 



8. Upper leaves with a strongly many toothed margin Plagiochila. 



Leaves 3-5 cleft Lophozia barbata. 



Leaves two-toothed or cleft 9- 



9. Plants minute, leafy stems less than 2 V inch wide; underleaves 



absent or so small as to be invisible with a lens; leaves 



round-ovate to obovate, cleft for at least ^ their length .. Cephalozia. 

 (Some small species of Lophozia may be sought here, 



but their leaves are less deeply cleft and the plants are a 



much darker green). 

 Leafy stems at least ^ inch wide; leaves two-toothed, but 



scarcely cleft i o. 



10. Leaves ascending, varying from bidentate to retuse or even 



entire near apex of stem; leafy stems & inch or more 



wide Lophocolea heterophylla. 



Leaves all two-toothed or cleft n . 



11. Leaves little longer than broad, concave, ascending 12. 



Leaves much longer than broad, oblong to subrectangular, 



lying flat on the ground; leafy stems at least -n, inch wide 13. 



12. Leaves subquadrate, inserted crosswise of the stem and sub- 



clasping Sphenolobus Michau.vii. 



Leaves roundish-ovate, inserted obliquely, not clasping. .^.Harpanthus. 



13. Underleaves so large as to be made out with a lens; perianth 



ascending from end of stem or branch .Lophocolea. 



Under leaves small and not discernible with a lens; perianth 



buried in the substratum, attached to the side of the stem . Geocalyx. 



