26 H. MOLHOLM HANSEN 
H Knautia arvensis Th Polygonum persicaria 
Th Lamium intermedium HH Potamogeton natans 
H Lathyrus pratensis Ph Rosa canina 
Th Linum catharticum Ch —  spinossissima 
G  Listera ovata HH: Ruppia maritima 
H Litorella uniflora H Sagina subulata 
H Lychnis flos cuculi H  Sangvisorba officinalis 
Th Myosotis hispida Ch Sedum acre 
Th — micrantha Th Senecio vulgaris 
Th == versicolor Th Sisymbrium sophia 
HH Myriophyllum verticillatum HH Sparganium minimum 
Ophioglossum vulgatum H  Succisa pratensis 
G Orchis latifolius H  Valeriana officinalis 
H  Phleum pratense HH Veronica anagallis 
H  Plantago lanceolata H  Vicia sepium 
Polypodium vulgare H Viola silvestris 
HH Polygonum amphibium Th — tricolor 
HH Zannichellia palustris. 
On the basis of particulars as to the proportion of each species 
in the floras of the above-mentioned countries, the Icelandic species 
were referred to one of the 7 species groups. While it is comparatively 
easy to place the species in the A or E groups, as this is only a 
question of ascertaining whether the main distribution of the species 
is above or below, north or south of three limits, the 20 °/o Ch bio- 
chore, a subdivision at the outset necessitates the selection of a pa- 
rallel of latitude, to the north of which the species do not occur. 
At each species group is stated the parallel of latitude selected as 
the upper limit of the species. In order to gain a comprehensive 
view of the extent to which it has been possible to gather the 
species into groups expressing adaptation to the arctic climate, the 
following conditions have been reviewed: — 1) The presence of the 
‚species groups in the floras of the different countries, 2) the distri- 
bution of the groups in Iceland, and 3) the content of Raunkizr’s 
life forms in each group. 
I. In table 4 are given the individual countries examined, be- 
ginning with those that are most arctic in character, as Ellesmere- 
land, North Greenland, and Spitsbergen, and ending with the most 
temperate. In the first column is stated the number of species which 
the country in question has in common with Iceland. The next 
two columns state how many of these species, common to both, 
belong to the A- and E-groups, and the last columns give particulars 
of the sub-groups. 
