318 THORODDSEN 



The Vegetation of the Coast-line. The halophilous plant- 

 associations 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 boulders, blown sand and 

 rocks of basalt and tuff. Very generally round the coast there is 

 seen upon low rocks 1 , at the foot, a belt of Verrncaria 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 offlcinalis, Plantago maritima, Armeria ma- 

 ritima and Glyceria distans. On steep, lofty coast- cliffs Cochlearia 

 officinalis and Rhodiola rosea oflen occur in great abundance, also 

 Silene maritima, Armeria maritima , Cerastinm alpinum and various 

 species of Poa and Festuca ; to these should be added Haloscias sco- 

 licnm in south-western Iceland and especially on the islands in 

 Breidifjordur. As is well-known, there are several large sea-fowl 

 cliffs along the coast of Iceland, but their vegetation has not yet 

 been investigated; H. Jonsson has investigated only a few smaller 

 sea-fowl cliffs in Dalasyssel and "sea-fowl-grass-slopes" (Fuglegraeslier) 

 in Skaftafellssyssel. According to H. Jonsson (1905, p. 37) the grass- 

 covered mountain-slopes in South Iceland frequented by sea-fowl 

 differ from the common grass-slopes, among other things in the 

 abundant occurrence of Poa pratensis and SteUaria media; the oc- 

 currence of Festuca elatior and Avena elatior on "sea-fow T l-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 

 extremelv difficult of access. 



^ 



253; XXVII, 1905. pp. 111 122). Th. Thoroddsen: Planteverdenen paa Island (Sal- 

 monsens Leksikon. IX, 1899, pp. 606 607). Helgi Jonsson: Studier over Ost-Is- 

 lands Vegetation (Bot. Tidsskr., XX, pp. 7789). Vegetationen paa Snaefellsnes (Vi- 

 densk. Medd. fra naturh. Foren. i Kobenhavn, 1900, pp. 1597). Vegetationen i Syd- 

 Island (Bot. Tidsskr.. XXVII, 1905, pp. 1 82) Vegetationen paa Island (Atlanten, 

 1904, pp. 41 50). Gro9rar- og JarSvegsrannsoknir (Bunagarrit XX, 1906, pp. 146- 

 181 ; XXIII. 1909, pp. 4154). Fyrirlestur urn groSur Islands (BtinaSarrit, XXI, 1907, 

 pp. 6 20). Bygging og Iff plantna, Kebenhavn, 1907, pp. 289 300. 

 1 Cf. Eug. Warming: Dansk Planteva-kst, I, K0benhavn, 1906. 



