Thread-moss 



Oblong nodding spore-cases, conspicuous- 

 ly ribbed when old, are borne on slender pedi- 

 cels. The ribbing of the cases has suggested 

 the name Aulacommum, from the Greek av\a%, 

 av\aKos, a furrow, and pviov, moss. There 

 are two rows of teeth, the inner with long 

 cilia. 



Nine species are known in all, five of them 

 in North America. 



Aulacomnium androgynum, Schwaegr. M.pnctatum,var. 



Habit and habitat. \n dense tufts, green ^ f tum - Margin of 

 above, rust-brown within, owing to the num- 

 erous felted hairs on the stems. Found on bare earth, roots of 

 trees, fissures of rocks, on plains or mountains. A tiny Western 

 humming-bird uses this moss for its nest. 



Name. The specific name, androgynum, hermaphrodite, was 

 given from a mistaken idea that the moss was produced only by 

 asexual methods, that is, by the gemmae, which are not the result 

 of fertilisation. The name is a compound of the Greek avrjp, 

 a8vpb<$, man, and jvvyj, woman. 



Plant (gametophyte). Dull-green, stems slender, rarely i^ 

 inches high, bearing red-brown felt-like filaments, and usually 

 producing slender leafless shoots terminating with round heads 

 of tiny granular bodies (gemma). 



Leaves. Narrowly taper-pointed; apex toothed; cells small, 

 round, with tiny projections on each face. 



Habit of flowering. Male and female flowers on separate 

 plants (dioicous). Male flower-clusters terminal, bud-like. 



Veil (calyptra). Reaching the middle of the spore-case; 

 long-beaked, split up one side. 



Spore-case. Brown, cylindrical-oblong, furrowed when old; 

 erect, finally horizontal. 



Pedicel (seta). f of an inch long. 

 Ltd (opercuhmi). Large, conical. 

 Annulus. Compound, rolling 

 back as the lid falls. 



Teeth (peristome). As in the 

 genus. 



Spores. Mature in summer. 

 Distribution. America, Europe. 



A. androgynum. Spore-case 

 with lid. 



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