THE HHYOFHYTA OF ICP:LAND 



503 



« (1 (( (i b h b 



Fig. 10. Poltitricliiiiu sc.vancinldrr Flocickc vnr. teiwUmii. 

 (I. in a damp. and h. in a dry condilioii (X 6). 



In lava clefts near Thingvellir and in decp lava clefts on Reykjarheidi 

 (at an altitude of about 250 metres) il was found abundanth' in several 

 piaces in association with several other Alpine species, for instance 

 Gymnomitriiim concinndlam, G. varians, Pleiivoclada albescens and Pohlia 

 cominiitala. The occurrcnce of this species in such localities is un- 

 doubtedly connected with the faet that there the conditions pertaining 



\\S 



i:! ,1 



/4/ 



b c d 



Fig. 11. Pohitrichum se.rangulare Floercke var. trnrlhim. 

 a. h and c. leavcs (\ 1.")): </. loaf-apex (X 100;. 



