THE BKYOPHYTA OF ICKLAM) oOl 



198. Pogonatum dentatum (Menz.) Brid. 

 Var. minus (Wahlb.) Hagen. 



Reykjavik.'. 



Here it grew in several piaces on pealy soil, and in one place vcry 

 abunciantly, with numerous capsule.s, some of which were almost ripe 

 in the lirst half of Aiigii-st. 



199. Pogonatum urnigerum (L.) P. B. 

 Pohjlrichiim iirnif/eriiin L. 



Widely di.stributed over the whole of Iceland. 



Grows iisually scattered as individual piants, or a few piants to- 

 gether, among other niosses on dry, humus-covered rocks or on tlie 

 ground, both dry and somewhat damp; for instance along the banks of 

 streanis. It occurs in large quantities on peat, often forming large light- 

 green patches, interwoven with Alicnlaria scalaris and, occasionally, Sca- 

 pania carla. On somewhat damp, moss-grown slopes it often forms 

 large tufts several centimetres high among Hijlocomiam spp., Ilijpniim 

 iincinatiim and Polijtrichiim alpiniim- such vigorous forms are also fre- 

 quently met with in South Iceland on somewhat damp ground, for in- 

 stance by the sides of ditches. It is most frequent in the lowlands and 

 does not appear to ascend above 300—400 metres. The fruit, which 

 only occurs on large piants growing in tufls, was ripe or overripe in 

 the beginning of June. 



200. Polytrichum alpinum L. 



Very common everywhere both- on dry and on somewhat damp 

 ground, and almost equally frequent from the sea-level up to the limit 

 of vegetation on mountain heights. It grows both mixed with species 

 of Hylocomiiim and interspersed in Rhacomitriiim-mals on knoils in bogs, 

 on peat, in grass-fields and on the stony slopes of mountain heights. 

 The fruit, which occurs vcry frequently, ripens in the lowlands about 

 August Ist. 



Varies considerably in habit, length of leaf, form of capsule, etc, 

 but the majority of the forms, however, approach closest to the type. 

 Forms agreeing more or less with var. septemtrionale Sw.) Brid. are 

 also common. 



201. Polytrichum formosum Hedw. 



W. Iceland: "Sæluhusid" in Sokkolfdalur (F.)!, sterile. 



202. Polytrichum gracile Dicks. 



Rather common over the whole of Iceland. 



This species grows in peaty soil, often abundantly, and sets fruit 

 almost always. It occurs only in the Iow land and has hardly been 



