558 A. HESSELBO 



Hepaticæ 



*Pellia Neesiana *Lophozia quinquedentata 



*Aneura pinguis — quadriloba 



* — multifida — Schultzii 

 *Cephalozia bicuspidata — Hornschuchiana 



* — pleniceps *Scapania irrigua 

 *Cephaloz{ella 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 aie met with 

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

 common in some districts and absent from others, for instance 

 Thuidmm 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 Campylopiis 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 

 Catoscopiiim, Philonotis, Cinclidiiim or Mniiim 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, 

 Mniiim cinclidioides or Cinclidiiim stygium, and in South Iceland by 

 Mniiim Seligeri. In North and East Iceland it is especially Thii- 

 idium lanatum which is often the most conspicuous species. 



Sphagnum spp. grow almost always in scattered tufts, and 

 Sphagnum bogs proper are rarely met with. Helgi Jonsson 

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

 curred on sloping ground and were composed of Sphagnum teres, 

 S. Warnstorffii and S. Girgensohnii intermixed with Paludella sqiiar- 

 rosa, Hypnuni stramineiim, Hylocomium squarrosum and Polytrichum 

 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 rubelliim and S. Warnstorffii intermixed with a few other 

 mosses, especially Thuidium lanatum, Hylocomium squarrosum and 

 Hypnum stramineiim. 



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

 formation of the myri, the large Sphagnum-cu?,h\o\\?> being inter- 



