THE BHYOPHYIA Ol" ICELAM) o21 



to oc'cur more particularly in the lava-delds, for instance near Hafnar- 

 fjordur. Thingvallahraun and Kihlhraun. It is foiind rather frequently 

 in fruit. 



253. Brachythecium glareosum (Bruch) Br. eur. 



Hijpniim glareosum liruch. 



E. Iceland: Seydisfjordur, on stonesl. X. Iceland: Tven'i m Oxna- 

 dalur. on damp gravelly ground!. W. Iceland: Botnsdalur, ianip 



rocks!. 



254. Brachythecium albicans (Xeck.) Br. eur. 



Hypnum albicans Neck. 



Commonly distributcd over the whole of Iceland. 



This species grows on a dry substratum, for instance on sandy or 

 grass-covered ground, on soil-covered stones, on dikes and on the peat- 

 walls of houses. It is most frequent in the low land up to a height 

 of about 300 metres, but occasionally, for instance near Akureyri, it 

 ascends as high as about 600 metres above sea-level. Only sterile speci- 

 mens have been found. 



255. Brachythecium erythrorrhizon Br. eur. 



Hypnum erythrorrhizon Hartm. 



N. Iceland: Hof near Ej'jafjordur ^O. D.)I; Ljosavatnl; Tverå in 

 Oxnadalurl. W. Iceland: Esja!. 



Found in all the localities only scantily intermixed in the tufts of 

 other mosses on rather dry ground. Near Ljosavatn it grew in the 

 Bcliila nana heath in association with Hylocomium proliferum. Hypnum 

 uncinatiim, Helerocladium squarrosulnm and Lophozia lycopodioides : in 

 Esja it grew on a slope with a southern exposure, in company with 

 Hylocomium spp. and Hypnum imponens. 



256. Brachythecium rivulare (Bruch) Br. eur. 



Hypnum rivulare Bruch. 



Ver%' comnion over the whole of Iceland. 



One of the most frequent mosses, which occurs everywhere on 

 damp ground up to about 400—500 metres above sea-level. It occurs 

 both in large and small streams, where it covers the stones or the 

 gravelly soil along the banks with its exlensive mats, and in bogs. and 

 is also one of the species which is most frequently met with in moss 

 bogs. Occasionally, however, it grows also on a more dry substratum, 

 for instance on soil-covered rocks and among grass. Onh' sterile speci- 

 mens have been found. 



The Botany of Iceland. Vol. I. part II. 34 



