300 



Wagner, A., 1907: Über die Anpassung ... von M. verticillatum. Zeitschr. 

 f. d. Ausbau d. Entwickelung (has not been at my disposal). 



Warming, E., 1884: Om Skudbygning, Overvintring og Foryngelse. Natur- 

 historisk Forenings Festskrift. Kjøbeiihavn. 



— 1886: Om Bygningen og den formodede Bestøvningsmaade af nogle 

 grønlandske Blomster. Oversigt over D. K. danske Videnskabernes Selskabs 

 Forhandlinger. Kjøbenhavn. 



— 1886—87: Om Grønlands Vegetation. Medd. om Grønland. XII. Kjøben- 

 havn. 



~ 1909: Oecology of plants. Oxford. 

 Warxstorff, c, 1896: Blütenbiologische Beobachtungen aus der Ruppiner 



Flora. Verh. d. bot. Vereins zu Brandenburg. 

 Winge, see Ferdinandsen. 



Hippuridaceae. 



Hii)puris vulgaris L. 



Herbarium material from East and West Greenland and 

 Iceland, as also in small quantity from Finmark, Lapland, Nova 

 Zembla and Waigatsch, further, alcohol material from Greenland 

 and Iceland. 



In Greenland Hippuris is the commonest, phanerogamic 

 water-plant, and it is on the whole the most wide-spread in 

 Arctic regions, according to the reports of botanists. The most 

 northerly place where it has been found is Danmarks Havn, 

 76°77'N. L., where it was in the flowering condition when taken 

 by the Danmark Expedition in the month of July (Ostenfeld 

 1910 p. 29). Mr. Lundager's photograph of the vegetation here 

 which he has kindly allowed me to see, shows it in very shallow 

 water, which is said to have sunk a great deal since the early 

 summer; otherwise it would seem remarkable that the broad, 

 short leaves, which in Denmark are found as a rule under 

 water, are here seen on a large piece of the emerged part of the 

 stalk. The picture also shows with great clearness the slight 

 development of the Arctic plants in comparison with the Danish. 

 Kruuse (1905 p. 151) found it most frequently in water of less 



