328 



have finished collecting at that time. The material of C. stag- 

 nalis from Kvannasund (the Færoes) Novb. 4. still contains fruits 

 in situ and even that of C. hamulata from Vallanes, Iceland, 

 January 10 (cf. p. 320), bears both pistillate and staminate flowers; 

 both have been gathered by H. Jonsson. 



The monoecious flowers are placed in the axil, ordinarily 

 one flower in each of them ; in some 

 cases a staminate and a pistillate flower 

 are found in the same axil. 



The arrangement is often the following 

 (cf. Hegelmaier 1 864 p. 36) ; low on the stem, 

 i. e. early developed, pistillate flowers, 

 higher on the stem, i. e. later developed, 

 staminate ones and in the middle part a 

 pistillate flower in one corner and a 

 staminate flower in the other corner of 

 the same pair of leaves, e. g. in C. 

 hamulata from a river, Bjørnedal at 

 Ivigtut, South Greenland. 



The pollen from the only stamen 

 of the male-flower is transported to the 

 two long and thin stigmas, covered in 

 most part of the length with oblong 

 Fig. 18. Callifriche papillae, by the wind according to Kntjth 

 longisfyla Norman? ^^^ ^ji^g^ authors, while some authors 



(Alten, Finmark) (X ca. S). 

 * staminate flower. 6 pistillate SUppOSC hydrOphiW and CntOmOphily tO 



flower. 



take place. 



The stigmas of the above-mentioned form from Alten, Finmark 

 — possibly C.longist'i/la, Norman — are exceedingly long (Fig. 18). 



The stigmas of the flowers of C. stagnalis (gathered by 

 C. H. Ostenfeld at Laugarne near Reykjavik, Iceland, Aug. 7. 1895, 

 are longer than the fruit, while those of other flowers were 

 shorter or of the same length as the fruit, as is common in 

 this species. Warnstorff (1896 p. 27) observed flowers with 



