The Botany of Iceland - 01.12.1914, Side 112

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THORODDSEN
have 237 species in common. Oí’ the higher plants in Iceland the
majority of the species belong to the Cyperaceæ (44) and the
Gramineæ (40), and these two l'amilies are also most characteristic
of the inhabited land and of the greatest importance as regards the
sustenance of the inhabitants. Of Compositæ there are 25 species,
of Caryophyllaceæ 24, Cruciferæ 22, Juncaceæ 17, Filices 17, Rosaceæ
16, Scrophulariaceæ 13, Papilionaceæ 12, etc.1 The lower plants have
not yet been closely investigated; there are known, however, 300
species ol' mosses, 233 species of lichens and 543 species of fungi,
452 of which are parasites; on Betula odorata have been found 54
species of parasites, on Salix lanata 14 species, on Dryas octopetala
11, and on Betula nana and Salix gtauca 10, etc. The mushrooms,
of which many occur, are as yet but slightly known.2
Naturally, nothing is known as to how many species have
immigrated into Iceland since the first colonization of the island in
874, but we may take for granted tliat the nnmber is considerable.
Even by the first “Landnáinsmen” several species were undoubtedly
imported from Norway and perhaps also from the islands along
Scotland. In the Sagas we read about live-stock (cows, horses, sheep
and swine) being bronght to Iceland and in the fodder brought
along with them there were certainly several foreign seeds. Some
of the immigrants for religious reasons, brought eartli with them
froin Norway from the site of their former temple (Hof). Then the
settlers also used foreign seed for cereal crops, on the cultivation
of whicli they wære very keen at first. Moreover, different species
may have been introduced along with articles of commerce and in
other ways. Of imported species, which during later centuries have
gained a firm footing and have become naturalized, the most com-
mon are Urtica urens, U. dioeca, Cirsium arvense, Spergula arvensis,
Carum carvi, Lamium intermedium, Senecio vulgaris and some others.
1 Eug. Warming: Tabellarisk Oversigt over Grönlands, Islands og Færöernes
Flora, 1887. (Vidensk. Meddel. fra den naturhist. Foren., 1887, Köbenhavn, 1888).
2 Chr. Grönlund: Islandske Naturforhold med særligt Hensyn til Mosvæxtens
Betydning for Landskabet (Tidsskrift for populære Fremstillinger af Naturviden-
skaben, 5. Række, IV, 1877, pp. 321—356). Bidrag til Oplysning om Islands Flora,
Lichenes, Hepaticæ og Musci (Bot. Tidsskr., IV, 1870, pp. 147—172; 2. Række, III,
1873, pp. 1—26). Afsluttende Bidrag til Oplysning om Islands Flora, Musci, Hepa-
ticæ, Lichenes (Bot. Tidsskr., XIV, 1885, pp. 159—217). Tillæg til Islands Krypto-
gamflora, indeholdende Lichenes, Hepaticæ og Musci (Bot. Tidsskr., XX, 1895, pp.
90—115). Islandske Svampe samlede 1876 af Chr. Grönlund (Bot. Tidsskr., XI,
1879—80, pp. 72—76). E. Rostrup: Islands Svampe (Bot. Tidsskr., XIV, 1885, pp.
218—229; XXV, 1903, pp. 281—335).