Thread-moss 



Habit of flowering. Male and female flowers on separate 

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

 Veil (calyptra). Split up one side. 

 Spore-case. Oblong, unsymmetrical. 

 Pedicel. i to 2 inches long. 

 Lid (operculnm). Conical. 

 Annulus. Large, compound, rolling 

 back as the lid falls. 



Teeth (peristome). Long, acute, the seg- 

 ments of the inner membrane about as long, 

 with 3 to 4 cilia intermediate. 



Spores. Maturing in early summer. 

 Distribution. Universal. 

 Aulacomnium heterostichum, Bruch & 

 Schimp. See Plate XX. 



Habit and habitat. In wide pale- 

 green tufts on shady banks and slopes in 

 the woods. 



Name. The specific name, hetero- 

 stichum, is a compound of two Greek 

 words, erepo?, other, and O-TI^O?, rank, 

 referring to two kinds of leaves. 



Plant (gametophyte). Stems densely 

 covered with red-brown filaments (to- 

 mentose). 



Leaves. --Inclined to one side; lower 

 obovate, upper gradually longer and ob- 

 ovate-oblong, incurved on one side; apex 

 nearly flat, obtusely pointed (apiculate) ; 



A. androgynum. 

 Old spore-case. 

 (Seepage 235.) 



Lid 



spore-case 



with lid. 



Veil. 



Cross section of central 

 strand of stem. 



A. palustre 



Cross section of leaf. Spore-case with veil. 



A. heterostichum. 



237 



