64 MOSSES WITH A HAND-LENS 



you will be almost sure to find a portion of it covered with the 

 dense mats of Gymnostomum which we might call, after the 

 manner of a well known Flora, the Toothless Twisted Moss, as 

 the generic name means, lacking a peristome. The dense mats 

 usually produce an abundance- of small ovoid capsules which 

 mature in autumn. The leaves are really less twisted than any 

 other genus of the family, hardly enough to be noticeable. 



G. CURVIROSTRE (Ehrh.) Hedw. This is apparently our most 

 common species as well as our largest. The plants sometimes 

 reach a length of 4 inches. The leaves are scarcely twisted when 

 dry, narrowly lanceolate, acute, with one margin, at least, 

 recurved. The seta is usually longer than in the other species; 

 capsule dark red-brown, glossy, thick-walled, widest at mouth 

 when dry and empty. The operculum remains attached to the 

 columella after separating from the urn and is thus attached for 

 some time. The spores mature in late summer or autumn. 



This species and the next are very closely related and are 

 often confused. If collected in autumn or winter this species is 

 readily distinguished by reason of the fact that the operculum 

 remains attached to the columella after dehiscence. I have found 

 opercula as late as May or June when the young sporophytes 

 were beginning to appear. When moistened the capsule-walls 

 and the operculum swell so as to again close the capsule and 

 thus do the work ordinarily done by the peristome. 



G. RUPESTRE Schleich. is distinguished from the preceding by 

 the broader-pointed, plane-margined leaves, the shorter seta, and 

 the thin-walled, yellowish-brown capsule and by the completely 

 virostre. 



WEISIA. 



The Weisias are small mosses growing in tufts or mats on 

 soil, especially rather dry sandy soil with our species, freely branch- 

 ing; the upper leaves are usually much larger than the lower, 

 erect-spreading, strongly crispate when dry, elongated- 

 lanceolate with the costa usually excurrent into a short point; 

 capsule well exserted on a seta of moderate length, usually erect 

 and symmetric, ovoid, plicate when dry and empty. 



W. VIRIDULA (L.) Hedw. is a species common in rather dry 



XVII. Gymnostomum curvirostre (From Bry. Eur.). 

 i and 2. Plants natural size. 12. Section of capsule. 



