218 OLAF GALL0K 



moss-vegetation (of Hylocomium proUjernin, H. trujuetrum, H. 

 sffimrrosnm, H. parietinnm and Climacinm dendroides). 



In Halsskogur I noted a vegetation consisting of various grasses, 

 of Arctostophylos, dwarf birches, Vacciniiun ulic/inosiim. Eqnisetuin, 

 linbus saxatilis, Empetrum and a few other plants. The ground \vas 

 in part covered with decaying birch-leaves, forming a layer of about 

 2 6 cm. in depth, and the trunks had an average height of about 

 3 metres. The ground there was quite devoid of lichens as were 

 also the trunks. 



The information contained in the literature on the subject, as 

 regards the ground-vegetation of coppices, is not very exhaustive, 

 and does not give much information with regard to how far lichens 

 occur or not. One must, however, expect that coppices, the floor of 

 which is occupied by heath-vegetation, can also harbour lichens, 

 but nothing concerning this is mentioned in the literature on the 

 subject, and I myself have not seen any coppices with an actual 

 ground-vegetation of heath. Nor is there any information to hand 

 as to how far grassland, mat-herbage or moss-carpets, when occur- 

 ring as ground-vegetation, shelter lichens. 



It is, however, certain that earth-lichens may occur here and 

 there, but even in the most favourable cases, they are but few in 

 number and physiognomic-ally little dominant. 



H. Jonsson mentions for instance "Cladonia-species" (which?) 

 as occurring near Breidibolstadir (South Iceland) and says that they 

 occur there "abundantly, but are far from playing so important a 

 part and from being so widely distributed, as in South Greenland." 



I myself only once found a small tuft of Cladonia pityrea. 



I do not doubt that, on the whole, the floor of the coppices 

 may be regarded as poor in, or devoid of, lichens and the reason 

 for this is undoubtedly to be found as usual, in the want of light 

 and in the leaf-fall. 



Nor does the ground-vegetation of willow-coppices appear to 

 include lichens. 



The epiphytic flora will be mentioned elsewhere, so I shall not 

 enter into the subject more fully here, \\here only the earth-lichens 

 of the plant-associations are being discussed. 



