w 



w 



vm] < RHIZOIDS ' OF BLADDERWORTS 99 



bladders, but their leaves are highly glandular and often bent 

 in a claw-like fashion 1 . They are firmer than the ordinary shoots 

 and do not collapse when lifted 

 from the water. Their function 

 is obscure, but it seems possible 

 that they play some part in 

 holding the inflorescence erect. 

 The Utricularias evidently have 

 a strong tendency towards the 

 production of specialised shoots 

 below the aerial part of the 

 flowering axis. Certain extra- 

 European members of the 

 genus (U. stellaris^ U. inflexa 

 and U. inflate. Fig. 150, p. 229) 

 have a wreath of air-containing 

 organs surrounding the base 

 of the inflorescence, and un- 

 doubtedly serving to keep it 

 erect in the water 2 . A vivid de- 

 scription is given by Spruce 3 , 

 in his account of his travels 

 on the Amazons, of a similar 

 arrangement in 7. quinqueradiata. This is a small species 

 with the usual submersed, finely divided leaves bearing 

 numerous bladders, but the flower-stalk, which is about two 

 inches high, has, midway, a large involucre of five horizontal 

 rays resembling the spokes of a wheel. This floats on the 

 surface and keeps the stalk always erect, and the solitary flower 

 well out of the water, " the whole recalling a floating night- 

 lamp, especially as the large yellow flower may be considered 

 to represent the flame." 



Reproduction by seed appears to be less important among 



iQoebel, K. (18892). 



2 Benjamin, L. (1848), Treviranus, L. C. (1848!) and Wight, R. 

 (1849). 3 Spruce, R. (1908). 



72 



R R 



FIG. 66. Utricularia neglecta, Lehm. 

 Base of inflorescence axis, /, with two 

 'rhizoids,' R. Three water-shoots, W, 

 cut away for simplicity. (Slightly re- 

 duced.) [After Gluck, H. (1906), Wasser- 

 und Sumpfgewachse, Bd. u, PI. IV, 

 Fig. 34 a.] 



