THE BRYOPHYTA OF ICELAND 541 



315. Hypnum sarmentosum Wahlb. 



Amblystegium sarmentosum I)e Not. 



Commonly distributed on boggy ground, but as a rule not plenti- 

 fully, mixed with other Hypnacece or in unmixed tufts. 



It varies considerably in size and colour. The slender High Alpine 

 forms, which occasionally form the bulk of the vegetation at an altitude 

 of 500700 metres, sometimes approach so close to H. strain ineum 

 that it may be difficult to keep these two species distinct from each 

 other. 



In S. Iceland it has been found in many places from about 300 me- 

 tres upwards, but it has not been found in the low land. In the other 

 parts of Iceland it is distributed from the low land up to about 

 700 metres above sea-level, but appears to be most frequent above a 

 height of about 200300 metres. It has been collected in fruit near 

 Hof in E. Iceland, Ljosavatn in N. Iceland where it occurred abundantly 

 in bogs at an altitude of about 250 300 metres, and near Grunnavik 

 in X\V. Iceland where it was the most abundant constituent of the 

 vegetation in a bog. The fruit, in the specimens from all these localities, 

 was green in the middle of Julv. 



*/ 



316. Hypnum trifarium W. et M. 

 Amblystegium trifarium De Not. 



E.Iceland: Seydisfjordur!; N. Iceland : Vatnsskard!. 



In both the above localities it was growing rather scantily on very 

 wet boggy ground, in company with Hypnum scoifyioides, H. stramineum 

 and H. revolvcns. 



317. Hypnum turgescens Th. Jensen. 

 Amblystegium turgescens Lindb. 



E. Iceland: Djupivogur!. N. Iceland : Svinadalur!. S. Iceland: Bar- 

 karstadr!, at an altitude of 530 metres. 



It grew everywhere abundantly on boggy ground, in company with 

 Hypnum revoluens, H. scorpioides and H. polygamum. 



318. Acrocladium cuspidatum (L.) Lindb. 



Hypnum cuspidatum L. 

 Verv common. 



V 



This species grows on more or less damp ground, especially in 

 bogs and damp meadows, but also in the water itself in moss bogs 

 and pools, or on damp rocks. As a rule it does not ascend higher 

 than 250 300 metres above sea-level. In S. Iceland it has been found, 

 however, in several places up to a height of about 500 metres. 



Fruit, which occurs rather frequently, was ripe about July 1st. 



