MOSSES WITH A HAND-LENS 41 



DICRANELLA. 



Plants small, like miniature Dicrana, scarcely branched. 

 Leaves lanceolate-subulate, without specialized angular cells. 

 Capsule short, erect or inclined, frequently striate ; lid beaked ; 

 peristome dicranoid, of 16 teeth, cleft to the middle into two 

 filiform divisions. 



The small size and narrow silky leaves, narrowed gradually 

 or abruptly from a broader base to a channelled subulate apex, 

 render the genus easy of recognition, especially if the dicranoid 

 capsule be present. The capsules present variations similar to 

 those of Dicranum, but capsules that remain erect and sym- 

 metric when dry and empty are rare; dioicous. 



KEY. 



1. Seta yellowish, sometimes becoming dark with 



age 2. 



Seta red 3. 



2. Capsule oblong, tapering at the neck, sulcate, 



mouth incurved when dry heteromalla. 



Capsule oblong, tapering at the neck, scarcely 



plicate, mouth erect when dry heteromalla Fitzgeraldii 



Capsule gibbous, strumose at neck, smooth 



when dry cerviculata. 



3. Leaves scarcely secund, not pellucid varia. 



Leaves secund or erect, pellucid by reason of 



very large thin-walled cells rufescens. 



D. HETEROMALLA (L.) Schimp. is our only common species. 

 It is found on shaded, sandy banks throughout our range. The 

 plants are simple or forked, one-half inch to two inches in 

 height, and grow in dense tufts or sheets of various shades of 

 green from bright yellowish to dark. The leaves are falcate- 

 secund. gradually narrowed from the base so that the lower 

 portion of the leaf has a triangular form ; the upper part is 

 subulate, and channelled with costa percurrent or excurrent. 

 The seta is yellow, becoming dark with age; capsule oblong to 

 oblong-ovoid, suberect, typically slightly curved, brown when 

 dry and empty, and furrowed and constricted below the mouth 

 ivith the mouth oblique in a very characteristic manner; oper- 

 culum rostrate, oblique. 



The obliquity of the mouth and the deepness of the fur- 

 rows in the capsule walls seem to be progressive with age. The 

 capsules mature in November and December, but do not as a 

 rule appear to assume their characteristic pose until spring. This 

 fact accounts for some of the discrepancies in descriptions, 

 especially of the varieties, although the species as a whole is 

 exceedingly variable. 



