78 A MANUAL OF MOSSES 



Key to Genera. 



a. Dorsal lamina very narrow: peristome none: stem radiculose- 



bulbiform at base. i. Bryoxiphium. 



a. Dorsal lamina usually broad: peristome present: stem not radi- 

 culose-bulbiform at base. b. 



b. Mostly not aquatic, sometimes submerged but floating. 



2. Fissidens. 

 b. Aquatic, filiform, floating mosses. 3. Octodiceras. 



I. BRYOXIPHIUM. Mitten. 



(Btistichia Bridel). 



Slender, dioicous, more or less densely silky-cespitose, 

 bright green or yellowish : stem stiff, oval in cross-section, 

 with central strand, radiculose at the extreme base, up\vardly 

 flattened, with distichous, closely imbricated leaves, simple or 

 irregularly branched ; leaves from a linear-lanceolate base. 

 either linear, with a small acumen, or rounded and abruptly 

 more or less long-subulate, denticulate above ; costa percurrent, 

 with a very narrow dorsal wing which does not extend to the 

 base of the leaf ; basal leaf-cells hyaline, rectangular, upper 

 cells chlorophyllose, triangular to irregularly trapezoidal, 

 smooth, towards the margin linear and forming a distinct 

 border; perichtetium terminal, with two concave, ovate, pro- 

 longed-acuminate, serrulate leaves with a complete dorsal 

 wing: seta shorter than the perichsetial leaves, flexuous or 

 cygneous ; capsule spherical, oval or obovate, smooth ; no 

 peristome or annulus ; spores .015-.020 mm. operculum 

 abruptly and irregularly rostrate; calyptra smooth, covering 

 about one-third of the urn ; antheridial plants similar in appear- 

 ance to the archegonial. 



Three species ; one in Mexico, one in Asia, and one in 

 Europe and the United States, rare. 



1. Bryoxiphium norvegicum [Bridel] Mitten. 

 {Bustichia norvegica Mueller). 



Plants 1-2.5 cm. long, somewhat flexuous, flat, lustrous, 

 yellow, fastened to vertical sandstone cliffs by a radiculose 

 bulbiform base; stems mostly simple; leaves short-acuminate 

 and as described for the genus ; costa vanishing at or near the 

 apex : seta rather thick, about 2 mm. long ; capsule obovate, 

 pale yellow, mouth reddish, peristome none; operculum 

 reddish at base, attached to columella and long-persistent ; 

 calyptra cucullate, large, tipped with a slender beak. 



On shaded vertical exposiires of sandstone in Wisconsin, 

 Kentucky and Central Ohio, also in Iceland, and once in Penn- 

 sylvania. 



Lawrence : "Slippery Rock Creek, Lesquereux." (Por- 

 ter's Catalogue). The writer has not been 



