LICHENOLOGY OF ICELAND 209 



species of Salix, etc.); there occurred also a small amount of mosses 

 (F % 20), and some lichens (F % 45). 



It was distinctly seen, that here all vegetation, both phanero- 

 gamic and cryptogamic, was greatly retarded by the long-lasting 

 snow-covering, and by the fact that the soil was very wet and cold 

 during the growth-period. 



The following -species occurred : 



Stereocaulon spp. (poorly developed) (fruticose lichen; sterile). 

 Peltigera rufescens (foliaceous lichen; sterile). 



aphtosa ). 



lepidophora ( ). 



Leptogium lacerum ( ; ). 



Psoroma hypnorum (crustaceous lichen; fertile). 



In order to obtain a general view of the subject, some typical 

 tables are given here in w r hich the different kinds of heaths are 

 presented in tabular form. They are resumes of the preceding text. 



Type I a. 



(Dry heaths on level (not knollyl ground; rich in phanerogams; devoid of, 



or poor in, lichens). 



Ex. 1. Heath near Hals parsonage (North Iceland). 



Dwarf birch F /o 100 Dryas (a small amount) 



Empetrum F % 100 Arctostaphylos. (a small amount) 



Grasses F % 100 Lichens F /o 



Ex. 2. Heath between Svinadalr and As (North Iceland). 



Dwarf birch F /o 1 00 Salix spp F % 20 



Glumiflora; F /o 100 Equisetum F % 20 



Empetrum F % 95 Calluna F % 7 



Vaccinium uliginosum . F /o 80 Lycopodium F /o 7 



Salix lanata F /o 60 Mosses F % 13 



Geranium silvaticum.. . F % 26 Lichens F o 



Betula pubescens F /o 20 



Ex.3. Heath near Einarstadir (North Iceland). 



Dwarf birch F % 95 Dryas F % 45 



Empetrum F , o 90 Salix lanata F /o 30 



Glumiflorae F /o 85 Calluna F /o 10 



Vaccinium uliginosum.. . F , o 65 Lichens F % 20 



The Botany of Iceland. Vol. II. 14 



