The Botany of Iceland - 01.12.1914, Blaðsíða 134

318
THORODDSEN
The Vegetation of the Coast-line. The halophilous plant-
assoeiations along the greatly extended coast-line of Iceland have,
as in other places, a rather heterogeneous soil consisting of fine
and coarse strand sand, large pebbles or houlders, blown sand and ,
rocks of basalt and tuff. Very generally round the coast there is
seen upon low rocks1, at the foot, a belt of Verrucaria maura;
then come grey, yellow and green patches of several kinds of li-
chens; above this level only a few plants occur, mostly scattered
individuals of Cochlearia officinalis, Plantago maritima, Armeria ma-
ritima and Glyceria distans. On steep, lofty coast-cliífs Cochlearia
officinalis and Rhodiola rosea oflen occur in great abundance, also
Silene maritima, Armeria maritima, Cerastium alpinum and various
species of Poa and Festuca; to these should be added Haloscias sco-
ticum in south-western Iceland and especially on the islands in
Breidifjördur. As is well-known, there are several large sea-l'owl
cliífs along the coast of Iceland, but their vegetation has not yet
been investigated; H. Jónsson has investigated only a few smaller
sea-fowl cliffs in Dalasyssel and “sea-fowl-grass-slopes” (Fuglegræslier)
in Skaftafellssyssel. According to H. Jónsson (1905, p. 37) the grass-
covered mountain-slopes in South Iceland frequented by sea-fowl
differ from the comnion grass-slopes, among other things in the
abundant occurrence of Poa pratensis and Steltaria media; the oc-
currence of Festuca elatior and Avena elatior on “sea-fowl-grass-slopes”
is also characteristic of the latter. The vegetation of the lofty sea-
fowl cliffs appears principally to consist of the same plants as are
found on common coast-cliffs, for instance, Cochlearia, Rhodiola,
Archangelica, as also Oxyria and Stellaria; all growing luxuriantly.
Owing to the soil being manured there is an immigration of many
other species, especially from the grass-slope and the grassland;
these species grow as luxuriantly in rock crevices and on ledges
as in the most well-manured home-fields. Collections of plants
from these sea-fowl cliffs have never been made; the plants being
extremely difficult of access.
253; XXVII, 1905, pp. 111—122). Th. Thoroddsen: Planteverdenen paa Island (Sal-
monsens Leksikon, IX, 1899, pp. 606 -607). Helgi Jónsson: Studier over 0st-ls-
lands Vegetation (Bot. Tidsskr., XX, pp. 77—89). Vegetationen paa Snæfellsnes (Vi-
densk. Medd. fra naturh. Foren. i Kobenhavn, 1900, pp. 15—97). Vegetationen i Syd-
Island (Bot. Tidsskr.. XXVII, 1905, pp. 1 —82) Vegetationen paa Island (Atlanten,
1904, pp. 41—50). Gróðrar- og Jarðvegsrannsóknir (Búnaðarrit XX, 1906, pp. 146—
181; XXIII, 1909, pp. 41—54). Fyrirlestur um gróður Islands (Búnaðarrit, XXI, 1907,
pp. 6—20). Bygging og líf plantna, Kobenhavn, 1907, pp. 289—300.
1 Cf. Eug. Warming: Dansk Plantevækst, I, Kobenhavn, 1906.