LIbKAKY 



BOTANICAL 

 OAkUEN 



INTRODUCTION. 



ON THE KNOWLEDGE OF THE FRESH-WATER ALGÆ 



OF ICELAND. 



IN earlier papers on the Botany of Iceland a number of fresh- 

 water algae are mentioned. These statements are of no great 

 interest nowadays, more especially as, in most cases, it is impossible 

 to identify the species mentioned with the species we have now to 

 take into account. Lauder Lindsay (1861) has, however, under- 

 taken, by means of the hterature to collect all he could about the 

 Icelandic flora up to 1860, and it is evident that he has given him- 

 self no Httle trouble, partly in finding all the extant literature, partly 

 in unravelHng the synonymics of the species. 



On the basis of these studies he has compiled a list containing 

 89 species of algae, of which ca. 16 may be presumed to originale 

 from fresh water. The 7 of these species are Cyanophijceæ and the 

 rest Chiorophyceæ. Even the species mentioned by Lindsay are 

 not all easy to identify with the now recognised species, and there 

 is, of course, no guarantee whatever that the earlier authors have 

 determined the algae correctly. Lindsay himself is well aware of 

 this. A list of the Cyanophyceæ mentioned by Lindsay will be 

 found at the end of this work. 



Regarding the literature prior to 1860 I refer to Lindsay's 

 work that, inter alia, contains a list of literature. 



Lindsay, however, overlooked, in any case, two works on 

 Icelandic flora. Firstly Liebman's treatise "De islandske varme 

 Kilders Vegetation" ("The vegetation of the Icelandic hot springs") 

 1840, that demands a special remark as the algae therein mentioned 

 are illustrated in Flora Danica. Japetus Steenstrup had in 

 1839 — 40 been on a journey to Iceland, whence he, amongst other 

 things, brought home some algae samples from the hot springs. 

 Liebman examined the specimens and described 3 new species, 



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