498 



A. HESSELBO 



vik (Morch;!); near hot springs in Reykholtdalur (Grl. ;!); BorgarfjordurL 

 Common in S\V. and S. Iceland!. 



Commonly distributed in SE.. S. and W. Iceland from Lon in the 

 south-east to Borgarfjordur in the west. In N. Iceland it has been found 

 only near Eyjafjordur, and it has not been collected in XW. Iceland. 

 It grows sometimes on peat, sometimes on damp clayey ground, for 

 instance by sides of ditches, and is occasionally found in f fruit, which 

 about Reykjavik was quite undeveloped even in August. It is a de- 

 cidedly low-land species, and has not been found at a higher elevation 



Fig. 9. Catharinea nndnlata (L.) Web. var. thermophila (nat. size). 



than 50 100 metres above sea-level. The usual forms of this species 

 are low in growth, 12 cm. high, with leaves which are as a rule 

 46 mm. long, narrowly lanceolate, obtuse or shortly pointed, only 

 slightly undulate with a few spines at the back, and the margin often 

 with single teeth. 



Catharinea undnlata is one of the species which is found most fre- 

 quently and abundantly on warm ground, where it occurs in rather 

 divergent forms. Usually it resembles the southern woodland forms 

 with long, strongly undulating leaves, very rough at the back. A very 

 peculiar form is 



Var. thermophila n. var. 



Loose cushions as much as 10 cm. high. Leaves evenly distributed 

 along the whole length of the stem, or somewhat denser at the top, 

 often falcato-secund, 67 mm. long, linear-lanceolate, sharply pointed, 

 with 45 lamellae at the back. Lateral shoots are often developed along 



