XXXVI KEY TO THE GENERA. 



E. Cleistocarpous mosses with immersed capsule. 



/Plant growing from a persistent, green protonema 2 



\Protonema not persistent 3 



/Calyptra minute ; Is. nerveless, not or obscurely toothed .57. Nanomitrium 



^Calyptra larger ; Is. nerved, or nerveless and coarsely toothed ...58. Ephemerum 



/Capsule with a minute, persistent lid ; leaves curled when dry 42. Weisia 



3\Capsule without a distinct lid ; leaves scarcely curled 4 



{Leaves lanceolate-subulate, cells long and narrow 5 

 Leaves ovate, ovate-lanceolate, or obovate 6 



/Capsule globose, without any apiculus, spores few, large <?■ Archidium 



5\Capsule apiculate, spores numerous 10. Pleui idium 



i/Ls. serrate in upper half, nerve vanishing below apex .5g. Physcomitrella 



\Ls. entire, or toothed at apex only, nerve reaching apex or excurrent 7 



I Two or three inner perichsetial Is. very wide and concave, usually serrulate at 



' apex; capsule globose, not (or very minutely) apiculate 36. Acaulon 



Inner pericytial Is. less conspicuous, entire ; capsule apiculate .37. Phascum 



1 



F. Stegocarpous mosses with immersed capsule. 



/ Leaves nerveless 2 



\ Leaves single-nerved 4 



/Leaves complanate, more or less undulate 82. Neckera 



\ Leaves not complanate nor undulate 3 



/Aquatic plant ; leaves thin, tristichous 80. Fontinalis 



■'\Terrestrial plant; leaves firm, not tristichous .jj. Hedwigia 



/Lid minute, not separating; plant very small 42. Weisia 



4 \Lid larger, separating when ripe 5 



/Perichsetial leaves ciliate ; capsule oblique 8. Diphyscium 



-'\Perichfetial leaves not ciliate ; capsule regular 6 



, /Fruit on a short lateral branch 8/. Cryphcea 



\ Fruit terminal 7 



/ Peristome absent 22. Blindia 



' \Peristome present 8 



o/Capsule not striate ; peristome single 29. Grimmia 



\Capsule striate, or smooth with double peristome jo. Orthotrichum 



G. Peristome absent (or capsule cleistocarpous). 



/Seta curved 2 



\ Seta straight n 



fCapsule with a lid /0 . philonotis 



\Capsule cleistocarpous J7 . phascum 



/Capsule striate, furrowed when dry 4 g_ Zygodon 



•^Capsule smooth, or irregularly sulcate only when dry 4 



/ Leaves large, roundish, very obtuse ; cells lax .52. (Editodium 



*\ Plant without large, round, obtuse leaves r 



/Cells elongate, hexagonal, very lax and thin-walled 6 



5 \Cells more or less quadrate, or elongate but small and narrow ...y 



6 fLid conic; calyptra mitriform fa Physcomitrium 



(.Lid almost flat ; calyptra cucullate fa m p unar i a 



/Leaves ovate, oblong, or obovate, nerve usually excurrent 8 



'\Leaves lanceolate, linear, or subulate \\" m q 



fCalyptra long, cylindric, covering capsule; leaves large, opaque, with' large, 



8 1 T multlfid P a P' llse ■•;■■ ;; : 46. Encalypta 



y Leaves smooth or with smaller papilla; ; calyptra small .38. * Pottia 



For the Key to the species of Pottia see Addenda. 



