THE BRYOPHYI A OF ICELAND 407 



where the plant has been found on other than \varni ground is near 

 Thingvellir where it was growing in a ditch along the road to Hrafnagjfi, 

 on clay washed together into a heap; there it had for companions 

 Dicranella crispa, Didymodon rubellus, Encalyx subellipticus and tiny 

 plants of Pohlia, Bnjum, etc. 



FAM. EPIGONANTHE.E. 



17. Gymnomitrium coral lioides Nees. 



S. Iceland: Thingvellir (Stp.; Grl.;!); Seljaland (Stp.;!). SW. Iceland: 

 Reykjavik (Grl.;!); frequent in Esja!; Hafnarfjordur!. E. Iceland: frequent!. 

 N. Iceland: Akurevri!. 



*/ 



Occurs rather common!} 7 , but as a rule, not abundantly in SW., E. 

 and probably also X. Iceland; in NW. Iceland it has not yet been found. 

 It usually grows on the top of blocks of basalt and lava in small greyish 

 cushions, and rarely on the dry gravelly soil of Grzm/?i/a-heaths. On 

 the heath in Seljaland it occurred on blocks of basalt up to a height 

 of about 400 metres; in Esja it has been found up to about 500 metres. 

 Only sterile specimens have been found. 



18. Gymnomitrium concinnatum (Ligthf.) Corda. 

 Commonly distributed over the whole of Iceland. 



u 



In the lowlands it is especially common in the lava-fields, where 

 it grows both on the top of blocks of rock and in crevices and caves, 

 generally mixed with other Hepaticrc such as Lophozia alpestris, L. qnin- 

 qaedentata and Plcaroclada albescens v. islandica; but it is also frequently 

 met with in clefts mixed with other Bryophyta and creeping over stones. 

 But it has its greatest distribution from about 300 400 metres upwards 

 towards the snow-line, where it grows both on more or less damp 

 ground and on rocks either in low, extensive cushions or mixed with 

 other Bryophyta such as Lophozia alpestris, L. ventricosa, Plcuroclada 

 albescens, Dicraimm Blytlii and 1). fiilvellnm , usually also woven into 

 dense cushions of Conostomiim boreale. 



In NW. Iceland especially, where it is one of the most frequently 

 occurring Bryophyta, it grows on gravelly flats on mountain heights in 

 extensive carpets associated with Anthelia nivalis, Alicnlaria minor, Polij- 

 tricluun sexangulare and the other above-mentioned Bryophyta. Near 

 Seljaland, at about 650 metres, it was growing in great masses on 

 weathered basalt rocks associated with Marsnpella cmarginata, Pohj- 

 trichum sexangulare and Dicrannm Blyttii. 



Fruit not rare; it ripens, according to altitude, during June July. 



19. Gymnomitrium varians (Lindb.) Schiffner. 



NW. Iceland: Dyrafjordur! (at an altitude of about 350 metres^ on 

 damp gravelly ground; Reykjaheidi, in a lava-cleft!. Near DVrafjordur it was 

 growing abundantly in low, blackish-brown mats associated with Anthelia 

 niualis and Alicnlaria minor on ground saturated with melting snow. 



