The Distribution of the Irish Flora. 57 
“General Type of Distribution” and correspond largely (over 260 
species) to the plants of Watson’s British Type, although a certain 
number are Bfitish-English, English-British, or belong to others of 
Watson’s types. It will thus be seen that the “ Universal” plants of 
Ireland, which are not so widespread in Great Britain, have a more of 
less southern range in this latter island, except for Crepis paludosa, 
which is distinctly northern (Scottish-Highland). 
Coming now to the plants which show an aggregation or 
diminution in some part of the country, we first find a marked 
tendency towards a central or marginal distribution; this feature is 
not very noticeable in the flora of Great Britain and is due to the 
position of the non-calcareous rocks and mountain-groups around 
the edge of Ireland, whilst the central limestone portion is low-lying 
and possesses numerous bogs, marshes and lakes. It is accordingly 
possible to establish a “ Central Type of Distribution” for Ireland, 
for plants found chiefly in the central plain; this type has an area 
extending between a line joining the Shannon with Waterford on 
the south and another joining Sligo and Dundalk bays on the north. 
The plants concentrated around the edge of the island con¬ 
stitute a further “Marginal Type of Distribution,” whose most 
characteristic feature is its avoidance of the central plain. A number 
of plants of marginal distribution are restricted to limited areas or 
show a general increase towards north, south, east or west. Thus 
a line, running east and west and joining Galway and Dundalk bays, 
marks off the northern from the southern species; and it was found 
necessary to draw a further boundary line, running north and south 
through the cities of Londonderry and Cork, to divide the eastern 
from the western plants. These two intersecting lines define four 
further types of distribution, named after the four provinces of 
Ireland, in which each reaches its maximum development. The 
seven types of distribution, thus defined for Ireland are 1 General 
(Universal), 2 Central, 3 Marginal, 4 Ultonian, 5 Mumonian, 6 
Lagenian, 7 Connacian. 
To the Central type 38 species ( e.g. Stellaria palustris , Orchis 
Morio, Sium latifolium, Andromeda polifolia) are referred, which 
are all lowland ; of these eleven are aquatic and nine are marsh 
plants ; ten grow on pastures and dry ground, whilst two are bog 
plants. Further whereas eight are calcicole, none are calcifuge. 
Compared with their British distribution, the plants of this group 
are distinctly southern.—46 species (e.g. Hypericum elodes , Lobelia 
DortinanJia, Pinguicula lusitanica , Nitella translucens) are included 
