Greinar (Vísindafélag Íslendinga) - 01.01.1967, Blaðsíða 6

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of the settlement, but especially in last few decades along
with other foreign grasses.
Most of the foreign species that have become establish-
ed still grow predominantly close to the cultivated land
or around towns and farms. Away from human settle-
ments the native vegetation still holds its own against the
foreign species, although considerable changes have also
occurred here, as mentioned above. Several of the intro-
duced species, such as Lamium spp., Galeopsis spp. and
others florish especially in geothermal areas where they
may take on the character of weeds, though they are in-
conspicuous in other areas.
Of the foreign species of flowering plants that have be-
come permanently established in Iceland, almost all are
perennial. Almost all annual species and many perennial
only survive for a single summer in a given area and
then die out. Some are introduced each year into many
areas with grass seeds etc., but many of the species are
only introduced now and then at irregular intervals.
Foreign species recorded in Iceland in the period
1900—1948.
Stefánsson (1901) listed 44 species of foreign plants
that had been found growing in a wild state in Iceland,
but could not be said to have become permanently esta-
blished. These are (Icelandic names in brackets):
Hordeum distichum (tvíraðabygg)
Secále cereále (rúgur)
Phálaris canariensis (kanarígras)
Alopecurus pratensis (háliðagras)
Bromus secálinus (faxagras)
B. racemosus (faxagras)
B. brizaeformis (faxagras)
B. tectorum (faxagras)
Avena sativa (hafrar)
Holcus lanatus (loðgresi)
Polygonumtomentosum (lóblaðka)
P. convoívulus (vafsúra)
Chenopodium album (hélunjóli)
Agrostemma githago (akurstjarna)
Silene cucubálus (holurtarbróðir)
Cameline microcarpa (hárdoðra)
Thlaspi arvense (akursjóður)
Lepidium perfoliatum (akurperla)
L. ruderále (akurperla)
Conringia orientális (garðablaðka)
Sisymbrium áltissimum (desurt)
Brassipa rapa f. campestris (arfa-
næpa)
Sinapis arvensis (arfamustarður)
S.álba (hvítmustarður)
Raphanus raphanistrum (akur-
hreðka)
Erysium repandum (aronsvandar-
bróðir)
Málva boreális (kisuostur)