Fróðskaparrit - 01.01.1993, Blaðsíða 90

94 SALIX IN THE FAROE ISLANDS AND THEIR AFFINITY WITH THE POPULATIONS IN ICELAND
(1971) determined them all as Salix arctica
and as such they are shown in the Atlas of
Florae Europaea (Jalas and Suominen,
1976), but not in the Atlas of North Euro-
pean Vascular Plants (Hulten and Fries,
1986).
After examining this willow in the Faroe
Islands I adhere to the opinion of Skvortsov
that it belongs to Salix arctica. And as far as
I can conclude it is impossible to distin-
guish it from the Icelandic population of
Salix arctica as will be discussed later in
this paper. A peculiar fact in the Faroese
population is the unusually high proportion
of plants which I can not interpret other-
whise than either as hybrids of Salix arcti-
ca x herbacea or as indications of strong in-
trogression from S. herbacea in the popula-
tion of S. arctica. Morphological traces of
hybridization or introgression are very
prominent in 5 of the 16 specimens which
are known from the Faroe Islands and the
plant I collected in Villingadalsfjall is of
that type. The main habitus and size is sim-
ilar to Salix arctica but the leaves are
broadly obovate or roundish, obtuse or
truncate. They are glabrous beneath but
glabrescent above. The specimen is a fe-
male clone and the catkins are bome on a
long peduncle with 3-5 smallish leaves.
The capsules are pubescent with a short
style and rather short stigma lobes. The fer-
tility is low but this clone is not absolutely
sterile. I incline to regard it as a hybrid be-
cause of the low fertility. Cultivated plants
of this clone from Villingadalsfjall seem
very similar to a plant I collected some
years ago in the vicinity of Reykjavík and
has considered a hybrid of Salix arctica x
herbaca and clones from it are now pro-
duced in nurseries in Reykjavík as ground-
cover-plants under the culitvar name “Kál-
famóavíðir”.
When examining the environmental cir-
cumstances where Salix arctica grows it
becomes easy to understand how frequent-
ly the hybrids occur in the Faroe Islands.
The sixteen specimens are collected in 12
there are only one individual plant growing
and there are several kilometres between
the localities, and all around Salix herbacea
is common. It is almost inevitable that the
dioecious Salix arctica changes pollen with
the neighbouring S. herbacea.
The flora of the Faroe Islands changed
markedly when man arrived to the islands
with grazing creatures (Jóhansen, 1985;
1989). It is known that e.g. Salix phylicifo-
lia which today is extremely rare (Hansen,
1966) was common in many communities
but disappeared almost totally after settle-
ment. The sites of Salix arctica I visited
were all on small ledges on steep cliffs
hardly accessible for grazing creatures. Not
all of the localities where Salix arctica has
been collected have been rediscovered, but
I have been told that the circumstances are
the same in the other localities. This indi-
cates that the plants growing in the Faroe
Islands today are relicts of a much larger
population. If these relicts have lingered as
more or less isolated individuals since the
settlement it is understandable that a good
deal of the new generations consists of hy-
brids.