FISSIDENTACEAE 33 



L. glaucum (L.) Schimp. Common, forming dense rounded 

 cushions. 



L. albidum (Brid.) Lindb. The only specimen from our 

 range that I can locate is in the herbarium of the N. Y. Bot. 

 Gardens from Herb. J. Cardot, Leg. H. A. Green. The species 

 is distinctly a southern form and H. A. Green collected mostly 

 in the Southern States. I suspect that N. C. and N. J. got 

 confused in Herb. J. Cardot. It is reported from various 

 localities in N. J. in the Geol. Survey but I doubt the authen- 

 ticity 7 of the material. 



Family 9. FISSIDENTACEAE 



One of the most natural and easily recognized families. It 

 can be easily recognized even when sterile by the distichous 

 leaves, vertically placed and arranged in one plane, apparently 

 split along the basal portion of the upper edge and clasping the 

 stem and the lower edge of the leaf next above. The leaf-cells 

 are small, rounded or hexagonal. The sporophyte is lateral or 

 terminal, exserted; peristome like that of Dicranum, with six- 

 teen forked, highly colored teeth, which are often papillose 

 above. 



FISSIDENS Hedw. 



Two of our species, F. Julianus and F. Hallianus, are aquatic 

 or subaquatic; the others are terrestrial, growing with erect stems 

 on damp soil and stones. All have strongly costate leaves. 

 The sheathing base of the leaf is called the vaginant lamina; the 

 terminal lamella above the costa, the vertical lamina; and the 

 dorsal lamella, the inferior lamina. The leaves are often bor- 

 dered, sometimes with a number of elongated cells, much as in 

 Mnium, but, more frequently, with cells of the same shape and 

 size but of a different color. 



Key 



1 — Plants aquatic, filiform, floating 2 



Plants terrestrial or submerged, not floating 3 



2 — Plants large, 2 to 6 inches long, much branched, habit of Fontinalis. 



Julianus 

 Plants small, not exceeding ij4 inches, little branched Hallianus 



