BRYACEAE 7 I 



Nearly all the species are large handsome mosses, easily dis- 

 tinguished even when sterile. Moist shaded ground rich in 

 humus, or much decayed wood in moist shaded places, are 

 favorite habitats of the genus. 



Rhodobryum rosenm is the only plant likely to be confused 

 with Milium. 



Key 



i — Leaves not bordered or border very slight 2 



Leaves bordered 3 



2 — Plants large, leaves entire or very slightly serrate by projecting cells; 



leaf cells twice as long as broad, marginal cells linear. . . . cinclidioides 

 Plants much smaller, leaves usually serrate; leaf cells isodiametric 



(i. e., as broad as long) stellar e 



3 — Leaves entire 4 



Leaves serrate, with single teeth 5 



Leaves serrate, with teeth in pairs 8 



4 — Leaves costate to apex punclatum 



Costa vanishing below apex punctatum var. datum 



5 — Leaves serrate to base or nearly so; capsules clustered 6 



Leaves serrate in the upper J^ or % only cuspidatum 



6 — Teeth of leaf margins of 2-5 cells (except affine rugicum) ; operculum 



mammillate or apiculate 7 



Teeth of leaf margins very short; operculum strongly beaked, .rostratum 



7 — Dioicous; many marginal teeth of more than two cells affine 



Synoicous; marginal teeth shorter, few of more than two cells. . . .medium 



8 — Costa vanishing below apex hornum 



Costa reaching apex in upper leaves 9 



9 — Costa toothed on the back; dioicous 11 



Costa not toothed on the back; synoicous 10 



10 — Capsules sometimes clustered; peristome forming a conspicuous red- 

 brown band around the mouth of the deoperculate capsule, spinulosum 

 Capsules not clustered; peristome yellowish to brownish. . . .marginatum 



11 — Leaf cells hexagonal, small, about 12-15/A orthorrhynchum 



Leaf cells rounded at the corners, about 20/J- lycopodioides 



A. Serratae. Leaves bordered, serrate with single teeth. 



M. affine Bland. Much less frequent than the variety. 

 Several localities on Staten Island, E. G. B. (Bx)!; "Common," 

 Muse. App. 205; Bedford, E. G. B., Bx! 



Var. ciliare (Grev.) CM. Frequent in damp shaded places. 

 May. 



