STUDIES ON THE FLOWER AND EMBRYO OF 

 SPARGANIUM. 



BY DOUGLAS HOUGHTON CAMPBELL, 



Professor of Botany, Leland Stanford funior University . 



CONTENTS. 



Page. 



Plates XLVI-XLVIII. 



I. The Flower 295 



The Staininate Floiver 297 



The Pistillate Flower 298 



II. The Embryo-Sac 299 



III. Fertilization ■. 302 



IV. The Secondary Growth of the Antipodal Cells 303 



V. The Embryo 307 



VI. Abnormal Embryo-Sacs 318 



VII. Recapitulation 319 



VIII. The Affinities of Sparganium 321 



Bibliography 322 



Explanation of Plates 324 



The genus Sparganium Tourn. includes about a dozen 

 species distributed over the northern hemisphere, but also 

 represented in New Zealand and Australia. The genus is 

 a peculiar one, and there has been much diversity of opin- 

 ion as to its affinities with other Monocotyledons. It has 

 usually been associated with Typha in the family Typhacese, 

 but the present view (Engler and Prantl, 1889) is that it 

 should be considered the type of a separate family, Spar- 

 ganiacese, with the Pandanaceee or Screw-pines as its nearest 

 allies. 



The genus has not been extensively studied, but our 

 knowledge of the development of the flower and embryo 

 of the European S. ramosuni is fairly complete (Hegel- 

 maier, 1874; Dietz, 1887). The other species have, so far 

 as I know, been treated from the standpoints of the descrip- 

 tive botanist only, and no account of the embryo-sac has 



[293] July 15. 1899- 



