THE BRYOPHYTA OF ICELAND 461 



hair point. In the birch coppices oC NW. Iceland a form frequently 

 occurs on larger, scaltercfi stones which, in habit, reminds one of 

 R. fasciculare. The tufts are flat towards the cdge, dark-green ; the hair 

 ])oint is verj' short and often wanting. The forms from mountain 

 heights are often jct-blaek fvar. atrata) or — on damp gravelly flåts — 

 yellowish green at the top. and grow in exlcnsive, discontiniious mats, 

 a fcw cm. thick. The fruit, which is vcry common, ripens in the be- 

 ^inning of June. 



88. Rhacomitrium heterostichum (Hedw.) Brid. 



E. Iceland; Hornatjordur!; Hof!; Geithellirl; Berufjordiir!. N. Ice- 

 land: Akureyri!, at an altitude of 350 metres. NW. Iceland: Patreks- 

 fjordur!; Arngerdareyri!. Common in S. and \Y. Iceland!. 



Common throughout E. Iceland, from Berufjordur, and southwards 

 through the whole of S. and W. Iceland. 



In W. Iceland it occurs abundanth' at the head of Isafjordur, near 

 Arngerdareyri, but has not been collected about the fjord further out- 

 wards towards its entrance; it was also common by Patreksfjordur. It 

 appears to be more rare in N. Iceland. 



The i)lant grows most frequently on dry rocks, and more rarely 

 on those that are damp; it occurs in masses, for instance, in the lava 

 districts of S\V. Iceland. It is most common in the low land, but is, 

 however, also met with at about 600 metres above sea-level. Fruit 

 is rathcr common. 



89. Rhacomitrium microcarpum Brid. 

 Grimmia ramiilosu Lindb. 



X. Iceland: Hof by Ejjafjordur (O. D.)!, sterile. 



Recorded by Gronlund from Reykjavik and Husafell, but the 

 tipecimens in the Botanical Museum in Copenhagen must be referred to 

 R. canescens. 



90. Rhacomitrium canescens (Weis) Brid. 



Very common. 



Next to R. hypnoidcs the most widely distributed species, and met 

 with as frequently on mountain heights as in the low land, and in 

 numerous forms. It grows both on rocks and on carth. especially 

 where it is somewhat damp. In the "'Grimmia heath " it often covers 

 the more low-Iying tracts with its light yellowish-green to grcyisli-green 

 mats, while R. hypnoides grows in the more dry parts, but both species 

 often occur mixed. It is also the most abundant constituent of the vege- 

 tation on damp sandy or gravelly soil b}' streams, in grass-fields with 

 a poor soil, etc. Forms with the hair point entirely or alniost wanting 

 (/". cpilosa) are frequent in wet localities. 



Fruit is orily rarely and scantily met with. Near Hof in E. Ice- 

 land piants were found in the middle of June with old capsules, and 

 near Sugandafjordur about July Ist with j^et green capsules. 



