80 DICRANACE/E. 



1. Dicranella heteromalla Schp. (Bryum heteromallum Dill.) 



(Tab. XV. A.). 



In dense silky bright yellowish or dark green tufts or sheets, 

 pale below, ^-2 inches high. Stems simple or forked, leaves 

 falcato-secund, the upper hamate, more rarely erecto-patent ; 

 gradually narrowed upwards from the point of insertion, so that 

 the lower part of the leaf has a narrowly triangular form ; rarely 

 with a slightly more distinct, somewhat concave leaf-base ; upper 

 part of leaf subulate, channelled, faintly or sharply denticulate 

 at margin and back from the middle upward ; rarely entire to 

 near the apex, with a few teeth at the point ; margin plane. 

 Nerve \-\ width of leaf at base, broad above and occupying the 

 greater part of the subula, usually with a very narrow margin of 

 cells reaching nearly or quite to the apex, but often excurrent in 

 a denticulate point. Cells at base rectangular, 2-5 times as long 

 as broad, shortly rectangular above with the end walls oblique. 

 Perichstial bracts sheathing. Seta pale yellow, flexuose, \ to 1 

 inch long ; capsule elliptical-oblong, inclined, slightly curved, 

 glossy brown, smooth or very faintly striate ; when dry and 

 empty deeply plicate, constricted below the mouth in front, with 

 the mouth oblique and incurved, neck indistinct, gradually taper- 

 ing, not strumose. Lid subulate-rostrate, curved downwards. 

 Peristome large, teeth red, cleft to middle into two or three divi- 

 sions. Male plant smaller, leaves less falcate, forming a terminal 

 coma enclosing the inflorescence. 



Var. /3. stricta Schp. Leaves erecto-patent, straight ; seta 

 longer, flexuose. 



Var. y. interrupta B. & S. (Dicranum interruptum Hedw.). 

 Stem taller, 1-2 inches, more branched ; leaves sometimes in 

 interrupted tufts, patent or falcato-secund. 



Var. 8. sericea Schp. Short, in dense, bright or yellowish 

 green, soft, silky tufts. Leaves delicate, narrower, erecto-patent 

 or subsecund. 



Hab. Banks in woods, roadsides, sandy hollows, etc. , very common. The vars. 

 /8 and y rare. The var. 5 on sandstone rocks, almost always barren, rare. Fr. 

 winter. 



The commonest of our species and one of the most variable, but with a peculiar 

 habit which usually permits of its easy recognition. The empty capsule especially is 

 very distinct in its glossy surface with somewhat oblique furrows and in its tapering 

 neck and very oblique mouth; the yellow seta, too, distinguishes it at sight from all 

 but the next species ; it must be borne in mind that old capsules have the seta 

 blackish, as they themselves also become. Occasionally, especially in mountainous 



