[6] 
1 
or 
THE GENOTYPICAL RESPONSE OF THE PLANT 
nated under these supposed main varieties. The difficulties led FockE 
(1902) to advocate another course. He recommends the keeping apart 
of A. maritima and A. elongata, which he considers »good» species, 
and the bringing together of the variable rest under a third species: 
A. ambifaria. 
The treatment of the species in the systematic literature thus dif- 
fers according as the region covered by the handbook corresponds with 
a region covered by mainly one form or by many. Neuman and 
Marsson have felt the difficulties of the latter case, while for instance 
Biytr, (1874), writing upon the flora of Norway, where the above 
iype a has the largest distribution, readily makes this type a species 
(A. maritima) under which the remaining rarer forms are without 
trouble subordinated as less important varieties. 
7. MATERIAL AND CULTURES OF INLAND AND COAST 
FORMS OF HIERACIUM UMBELLATUM L. 
My attention was first drawn to the great variability of this species 
in 1917 while studying the distribution of different shore forms of in- 
land species along the north-west coast of Scania. Two types occur 
in this region both differing from the ordinary inland form growing in 
Scania. The latter is a tall plant, erect or almost erect, with lanceolate 
leaves, about 10 mm. wide, and with rather contracted inflorescences. 
It is a typical woodland form and occurs throughout the province, 
except for a narrow stretch of land along the sea and a few isolated 
localities in the interior to be dealt with in the following. The two 
types found along the north-west coast were both confined to distinct 
habitats, the one occupying rocky and much exposed points on the 
coast strip, the other growing on sand dunes in the epilittoral belt. In 
a previous publication (Turesson,1919 a) both forms were prelimina- 
rily classed as Hieracium umbellatum var. dunense Reyn. On that 
occasion the zonal distribution of plants accompaning the two forms 
was also dealt with (1 c. pp. 5 and 6). 
Most of the individuals belonging to the sand dune form have 
less erect stems — some are more or less prostrate and somewhat 
narrower leaves and less contracted inflorescences than the inland 
form. The cliff form is also more or less prostrate and has a bushy 
growth. When grown in cultures the leaves become much broader 
than those of the inland form. The inflorescences are also more ex- 
panded in the cliff form than in the inland form. 
There are three points within this north-west region where the 
Hereditas III. 19 
