The Botany of Iceland - 01.12.1942, Page 18

244
M. P. CHRISTIANSEN
against using a particular character, e.g. purple spots on the leaves, to
refer herbs with this character to one and the same species. Cultivation
has proved that a very large number of quite different species have
these spots; but unfortunately, individuals with this character, but
rather different in other respects have in our herbaria been referred to
the same species.
7. The Distribution of the Taraxacum-Species in lceland.
Considering the short time at my disposal, the vastness of the
country, and, not least, the fact that the Taraxacum-flora was mostly
unknown to me, it is matter of course that my investigations of the
distribution of the Icelandic Taraxaca in Iceland itself cannot be
exhaustive. On my second joumey, however, at which time I already
knew a fairly large number of the species occurring there, I was able
to make notes on the distribution of several species. In this connexion
I must emphasize that as a rule I only searched for the Taraxacum-
flora in the inhabited districts: The homefields and their nearest sur-
roundings, for instance heaths, moors, rock-ledges, banks of rivulets,
and a few birch-woods and birch-copses, while I only occasionally
searched in districts far from inhabited places, for instance the valleys
of Þórsmörk under Goðalandsjökull. The Taraxacum-ílorsi of the wastes
and the high mountains is still almost unknown. Species probably occur
there which I have not found. But as my studies in Iceland have been
extended to all districts of the country, with the exception of the centre
and the environs of the large Vatnajökull, I have been able to ascertain
that a few species have a wide distribution there, at least in all
inhabited districts. That was the case, for instance, with T. acromaurum
Dahlst. and T. islandicum Dahlst.; other species, on the other hand,
may have either a southerly or a northerly distribution. T. hoplites
M.P.Chr. is thus frequent in S.W. Iceland, while, in the northem part,
it is only found in the town of Akureyri itself, where a great many
occurred. It has probably been introduced. Another species, T. diluti-
squameum M.P.Chr. has only been found in N. Iceland where it was
frequent in several places. The same is the case with the species T. bra-
chycranum Dahlst., which is frequent in Akureyri along roads, and in
ditches; and in Blönduós in the homefield. On the other hand a number
of the observed species were only found occasionally, but then often in
quantity.
See also maps of distribution p. 254 and following.