Vol. 35 



i 



BULLETIN 



No 6 



OF THE 



TORREY BOTANICAL CLUB 



JUNE, 1908 



The development of the embryo-sac of Nymphaea advena * 



Sara Seaton g 



(WITH PLATES l8 AND 19) 



The taxonomic position of the water-lilies or Nymphaeaceae has 

 always been doubtful because of their peculiar and seemingly in- 

 consistent characteristics. The closed vascular bundles, irregularly 

 placed through the stem, are characteristic of monocotyledons, 

 but the reticulate venation of the large peltate leaves is a dicotyle- 

 donous character, while the flowers might belong to either class. 

 Moreover, the fruit presents peculiarities that have been interpreted 

 m various ways. Early investigators studied the seed of nearly or 

 quite mature fruit. Recent investigators, using younger material, 

 nave, by their studies of development, made clear points not 

 hitherto known. In 1901, H. L. Lyon declared that "the em- 



ryo of Nelmnbo is genuinely monocotyledonous in its develop- 

 ment. TKe plumule arises laterally and at first there is but one 

 cotyledon which later bifurcates to form the two fleshy bodies." 



n e fact that the radicle does not function is another respect in 

 which Nelumbo conforms to well-known monocotyledonous types. 



ecause of the characters of the embryo as well as of the mature 

 P ant, Lyon concluded that the Nymphaeaceae should be classified 

 among the monocotyledonous families in a subseries coordinate 

 with the Potamogetonineae, Alismineae, and Butomineae, in the 

 se n*es Helobiae. 



to 1902, M. T. Cook followed Lyon with his paper on the 

 m ryogeny of Cqstalia odorata and Nymphaea advena, in which 



h l c ^ fi rmed the views already given. 



904 



[Th 



Contribution from the Department of Botany of Cornell University, No. 128. 



283 



