The Botany of Iceland - 01.12.1942, Blaðsíða 24
250
M. P. CHRISTIANSEN
with thick, firm, strongly cobweb-hairy, and purple-spotted leaves,
long, strongly spreading outer bracts, and a fruit, at the summit very
longtoothed, with a long cylindrical pyramid (see plate VII). The
group contains many species, which seem to be closely related to T.
croceum Dahlst. coll., while other species differ in the type of leaf as
well as the form of the fruit from the true Spectabilia-species, as also
from croceum and the naevosum-iovms. Further, there are a number
of species resembling the Vulgaria-group in several characters. How-
ever, they cannot be classed with this group, which, indeed, is represented
in Iceland by introduced species. They differ from species of the Vul-
garia-group, for instance by always having big fruits. Gultivation also
shoved that they all have another shape than that common to Vul-
gan'a-species. These species form a connecting link between the distinct,
purple-spotted Icelandic species on the one hand and the ‘true’ Vulgaria-
species on the other hand. Here they will be placed in a new group,
Subvulgaria.
As will appear from the above, the boundaries between the different
Taraxacum-groups are not quite distinct; but there are not distinct
boundaries in nature, either. (A division into groups, however, is neces-
sary, or desirable, for convenience, as the number of Taraxacum-species
described of recent years has increased very much). Most of the Taraxa-
CMwr-species, however, are easily referred to a group, as they have the
characters typical of the group, but in other cases, it must to some
extent depend on an estimate, in which group they should be placed,
and finally there are species that are so characteristic that they can
hardly be classed with any group at all.
The Icelandic Taraxaca will here be referred to the following groups
of species:
Erythrosperma Dahlst. Naevosa M.P.Chr.
Macrodonta M.P.Chr.
Subvulgaria M.P.Chr.
Vulgaria Dahlst.
Fulva M.P.Chr.
Ceratophora Dahlst.
Crocea M.P.Chr.
Eu-Spectabilia M.P.Chr.
Concerning the demarcation of the groups see the key below and
the description of the groups preceding each key of the group.
2. Key to the Groups of Species.
a. Bracts with distinct appendage below the tip; fruits red, violet-red, fulvous, brown
or straw-coloured.