319 



in Iceland only in the surroundings of hot springs, thus at 

 Laugarne near Reykjavik in water of a temperature of ca. 25° 

 (Grønlund 1890 p. 140, Ostenfeld 1899 p. 238, Stefansson 1901 

 p. 117); the ubiquitous C. venia not with certainty on the 

 Færoes. In Greenland C. verna was found as far up the moun- 

 tains as ca. 166 m. above the sea, in Scoresby Sund ca. 70° 15' 

 N. L., East Greenland (Hartz 1895 p. 323). Hegelmaier notes 

 it from the Morteratsch glacier, Engadin (1. c). 



C. polijmorplia Lönnr. is mentioned from Greenland, but 

 as far as 1 am able to judge, this species consists of forms of 

 other species, viz. of C. verna and C. hamulata. 



C. autumnalis, gathered only a few times, has a low growth, 

 especially the species from Disco, West Greenland, ca. 70° N. L., 

 found by M. P. Porsild in a depth of 0,16 — 0,33 m, but those 

 from Iceland too; from the Faeroes there is but little material 

 of this species. It is only available in herbarium-specimens, 

 and for that reason not examined anatomically. 



Some peculiar plants gathered by Professor Warming July 6, 

 1885, in the river Alten, Finmark, appear to be C. longistyla 

 Norman (1895 p. 281), who has noted it only from one locality, 

 near to the same river at Raipas about 69°57 N. L. 



Callitriche is found in still as well as in running water, 

 C. verna also in dried-up places (e. g. Norman 1. c. p. 280), 

 which seems to be comparatively often the case in Greenland. 



C. aiitumnalis in lakes at Disco, ca. 70° N. L. (Porsild 1902 

 p. 206), was growing in patches together with Batrachium 

 paucistamineum and aquatic mosses, in shallow water as men- 

 tioned above. On the Færoes C. hamulata occurs mostly as 

 landform, but also grows in the L^Yore/Za-association in lakes, 

 and in streams (Ostenfeld 1901 p. 57, 1908 p. 140 — 142). 



The bottom in which seedlings of C. verna were observed 

 in a lake on Danmarks Island (70°27' N. L., East Greenland, 

 Hartz 1895 p. 278) consisted of gytje. It was sandy and muddy 

 in a pond with about 35 cm water, in which C. hamulata ktz. 



21* 



