558 A. HESSELBO 



Hepaticse 



*Pellia Neesiana *Lophozia quinquedentata 

 *Aneura pinguis quadriloba 



multifida Schultzii 



*Cephalozia bicuspidata Hornschuchiana 



pleniceps *Scapania irrigua 

 *Cephaloziella Hampeana uliginosa 



rubella undulata 



Odontoschisma elongatus *Blepharostoma trichophyllum 



*Alicularia scalaris *Anthelia julacea 

 *Lophozia Kunzeana 



In the above list an asterisk is prefixed to those species which 

 are common over the whole of Iceland, and which are met with 

 in almost every considerable boggy tract. Some of the species are 

 common in some districts and absent from others, for instance 

 Thuidium lanatum and Dissodon splachnoides, which are very com- 

 mon in North and East Iceland, but are rare or entirely absent 

 from other parts of the country, and Campylopus Schimperi, which 

 is found only in the southern part. 



The mosses often grow so much intermixed that a small collec- 

 tion may contain 15 20 or even more species, but often smaller 

 and larger patches are found dominated by a single species. Thus 

 Catoscopium, Philonotis } Cinclidiam or Mnium bogs occur, in each 

 of which one of these species is the dominant member. On very 

 damp ground the mass of the vegetation is formed by, for instance, 

 Mnium cinclidioides or Cinclidium stygium, and in South Iceland by 

 Mnium Seligeri. In North and East Iceland it is especially Thu- 

 idium lanatum which is often the most conspicuous species. 



Sphagnum spp. grow almost alw r ays in scattered tufts, and 

 Sphagnum bogs proper are rarely met with. Helgi Jonsson 

 (1900, p. 25) records such bogs from Snsefellsnes, where they oc- 

 curred on sloping ground and were composed of Sphagnum teres, 

 S. Warnstorffli and S. Girgensohnii intermixed with Paludella squar- 

 rosa, Hypnum stramineum, Hylocomium squarrosum and Polylrichum 

 commune. I have only seen a similar vegetation near Barkarstadr 

 in South Iceland, where, on a wet boggy slope stretching down 

 towards a river, there was an almost continuous growth of Sphag- 

 num rubellum and S. Warnstorffli intermixed with a few other 

 mosses, especially Thuidium lanatum, Hylocomium squarrosum and 

 Hypnum stramineum. 



Sphagnum spp. often play an important part in the knoll- 

 formation of the myri, the large Sp/iagrnu/n-cushions being inter- 



